Scenario Map: TCP/IP — 网卡缺失 (Network Adapter Missing)

Product/Service: Windows TCP/IP Stack
Scope: 网络适配器在系统中不可见或无法使用
Last Updated: 2026-03-11

1. 场景概述

网卡缺失是指 Windows 系统无法识别、加载或显示一个或多个网络适配器，导致网络连接完全不可用。此场景涵盖物理网卡、虚拟网卡（Hyper-V / VMware）、Wi-Fi 适配器等所有类型。

子场景分类 (Sub-types)

mindmap
  root((Network Adapter Missing))
    Adapter not shown in ncpa.cpl
      Network Connections window is empty
      Get-NetAdapter returns nothing
    Device Manager yellow/red icon
      Driver load failure
      Code 31 / Code 10 error
      Resource conflict
    Completely invisible adapter
      Hidden device not shown
      Ghost adapter from old hardware
      PnP enumeration failure
    Adapter shows Disabled
      Disabled by admin or policy
      Disabled by power management
      Disabled by Group Policy
    VM NIC removed or not attached
      Hyper-V vNIC missing
      VMware NIC not present
      VM generation mismatch
    Physical NIC hardware failure
      PCIe slot failure
      NIC LED not lighting up
      NIC not detected in BIOS
    Driver missing after OS upgrade
      In-place upgrade lost OEM driver
      Inbox driver not compatible
      Driver store corrupted

2. 典型症状

# 症状描述 影响范围
1 打开 ncpa.cpl（网络连接）显示 “No network adapters found” 或完全空白 所有网络连接不可用
2 Get-NetAdapter 返回空结果，无任何适配器列出 PowerShell 网络管理失效
3 设备管理器中网卡条目显示黄色感叹号（!）或红色叉号（×） 适配器存在但驱动加载失败
4 操作系统升级（如 Win10→Win11）后网卡驱动丢失 升级后无法联网
5 Hyper-V / VMware 虚拟机中找不到任何网卡 VM 无网络连接
6 适配器显示 “Network cable unplugged”，但之前一直正常工作 间歇性或永久断网
7 ipconfig /all 无任何适配器信息输出 无 IP 地址，DNS 不可用
8 系统托盘网络图标显示红色叉号，提示 “No connections available” 用户无法连接任何网络

3. 排查流程图

flowchart TD
    A["🔍 Start: Network Adapter Not Visible"] --> B{"Open Device Manager<br/>devmgmt.msc"}
    
    B -->|"NIC listed with<br/>yellow ! icon"| C["Check driver status<br/>Right-click → Properties"]
    B -->|"NIC listed but<br/>shows Disabled"| D["Right-click → Enable Device<br/>or: Enable-NetAdapter -Name *"]
    B -->|"NIC NOT listed<br/>at all"| E{"View → Show Hidden Devices<br/>set DEVMGR_SHOW_NONPRESENT_DEVICES=1"}
    
    C --> C1{"Driver error code?"}
    C1 -->|"Code 10/31:<br/>Cannot start"| C2["Uninstall driver completely<br/>pnputil /delete-driver oemXX.inf /uninstall<br/>Then: Scan for hardware changes"]
    C1 -->|"Code 28:<br/>No driver installed"| C3["Download driver from OEM website<br/>or: pnputil /add-driver driver.inf /install"]
    C1 -->|"Code 39/41:<br/>Driver corrupted"| C4["sfc /scannow<br/>DISM /Online /Cleanup-Image /RestoreHealth<br/>Then reinstall driver"]
    
    D --> D1{"Adapter appears<br/>in ncpa.cpl?"}
    D1 -->|"Yes"| D2["✅ Resolved: Adapter was disabled"]
    D1 -->|"No"| D3["Check Group Policy:<br/>gpedit.msc → Network Connections<br/>Check if adapter is hidden by policy"]
    
    E -->|"Ghost adapter found<br/>(grayed out)"| F["Right-click → Uninstall Device<br/>Remove ghost NIC<br/>Reboot and rescan"]
    E -->|"Still no adapter<br/>found"| G{"Check BIOS/UEFI Settings"}
    
    G -->|"NIC is Disabled<br/>in BIOS"| H["Enable NIC in BIOS<br/>Save settings and reboot"]
    G -->|"NIC is Enabled<br/>in BIOS"| I{"Physical or Virtual?"}
    
    I -->|"Physical Machine"| J["Check hardware:<br/>1. Reseat NIC in PCIe slot<br/>2. Try different PCIe slot<br/>3. Check NIC LED indicators<br/>4. Test NIC in another machine"]
    I -->|"Virtual Machine"| K{"Check VM Settings"}
    
    K -->|"Hyper-V"| K1["Hyper-V Manager → VM Settings<br/>Add Hardware → Network Adapter<br/>Select virtual switch"]
    K -->|"VMware"| K2["VM Settings → Add → Network Adapter<br/>Select network type:<br/>Bridged / NAT / Host-Only"]
    
    J --> J1{"NIC works in<br/>another machine?"}
    J1 -->|"Yes"| J2["Motherboard PCIe slot issue<br/>or: OS driver/registry corruption<br/>Try: netcfg -d (nuclear reset)"]
    J1 -->|"No"| J3["🔴 Hardware Failure<br/>Replace NIC"]
    
    C2 --> Z{"Adapter working<br/>after fix?"}
    C3 --> Z
    C4 --> Z
    F --> Z
    H --> Z
    K1 --> Z
    K2 --> Z
    
    Z -->|"Yes"| Z1["✅ Resolved"]
    Z -->|"No"| Z2["Nuclear Reset Options:<br/>1. netcfg -d<br/>2. netsh winsock reset<br/>3. WMI rebuild:<br/>winmgmt /resetrepository"]
    
    Z2 --> Z3{"Resolved after<br/>nuclear reset?"}
    Z3 -->|"Yes"| Z4["✅ Resolved after reset"]
    Z3 -->|"No"| Z5["🔴 Consider OS repair install<br/>or hardware replacement"]

4. 详细排查步骤与命令

Step 1: 检查适配器基本状态

# 列出所有网络适配器（包括隐藏的）
Get-NetAdapter -IncludeHidden

# 列出所有网络类别的 PnP 设备（包括有问题的设备）
Get-PnpDevice -Class Net

# 使用 pnputil 枚举所有网络类设备
pnputil /enum-devices /class Net

# 列出所有网络适配器的详细信息（WMI）
Get-WmiObject Win32_NetworkAdapter | Format-Table Name, NetConnectionStatus, PNPDeviceID -AutoSize

# 列出所有网络适配器配置信息
Get-WmiObject Win32_NetworkAdapterConfiguration | Where-Object { $_.IPEnabled } | Format-List Description, IPAddress, DHCPEnabled

Step 2: 检查驱动程序状态

# 列出所有已安装的网络驱动
dism /online /get-drivers /all | findstr /i "net"

# 检查驱动存储中的网络驱动 INF 文件
pnputil /enum-drivers | findstr /i "net"

# 查看特定设备的驱动详情
Get-PnpDeviceProperty -InstanceId "PCI\VEN_8086*" | Format-Table KeyName, Data -AutoSize

# 检查驱动签名状态
sigverif  # GUI 工具
# 或
driverquery /v | findstr /i "network"

Step 3: 在设备管理器中显示隐藏设备

:: 方法 1：设置环境变量后打开设备管理器
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
devmgmt.msc

:: 方法 2：PowerShell 方式
[Environment]::SetEnvironmentVariable("DEVMGR_SHOW_NONPRESENT_DEVICES", "1", "Process")
Start-Process devmgmt.msc

Step 4: 检查核心网络服务

# 检查 NDIS（网络驱动接口规范）服务状态
sc query NDIS

# 检查 Network Connections 服务
sc query Netman

# 检查 Network Store Interface 服务
sc query nsi

# 检查 WLAN AutoConfig（Wi-Fi 适配器需要）
sc query WlanSvc

# 检查所有网络相关服务
Get-Service | Where-Object { $_.DisplayName -match "network|ndis|wlan|net" } | Format-Table Name, Status, StartType -AutoSize

Step 5: 检查事件日志

# 查看与网卡相关的系统事件日志（最近 24 小时）
Get-WinEvent -FilterHashtable @{
    LogName = 'System'
    ProviderName = 'ndis', 'NetBT', 'Tcpip', 'e1iexpress', 'NETVSC'
    StartTime = (Get-Date).AddHours(-24)
} -ErrorAction SilentlyContinue | Format-Table TimeCreated, Id, LevelDisplayName, Message -Wrap

# 查看 PnP 相关事件（设备安装/移除）
Get-WinEvent -FilterHashtable @{
    LogName = 'System'
    ProviderName = 'Microsoft-Windows-Kernel-PnP'
    StartTime = (Get-Date).AddHours(-24)
} -ErrorAction SilentlyContinue | Select-Object -First 20 | Format-Table TimeCreated, Id, Message -Wrap

# 查看 Device Setup Manager 日志
Get-WinEvent -LogName 'Microsoft-Windows-DeviceSetupManager/Admin' -MaxEvents 20 -ErrorAction SilentlyContinue | Format-Table TimeCreated, Message -Wrap

Step 6: BIOS/固件和硬件检查

# 检查系统是否识别到网卡的 PCI 设备
Get-PnpDevice -Class Net -Status OK, Error, Degraded, Unknown | Format-Table FriendlyName, Status, InstanceId -AutoSize

# 检查 PCI 总线上的网络设备
Get-PnpDevice | Where-Object { $_.InstanceId -match "PCI\\VEN" -and $_.Class -eq "Net" }

# 查看网卡硬件 ID（即使驱动未加载也可见）
pnputil /enum-devices /class Net /drivers

Step 7: 虚拟机专用检查

# Hyper-V: 检查 VM 的网络适配器配置
Get-VMNetworkAdapter -VMName "YourVMName"

# Hyper-V: 列出所有虚拟交换机
Get-VMSwitch

# Hyper-V: 为 VM 添加网络适配器
Add-VMNetworkAdapter -VMName "YourVMName" -SwitchName "YourSwitch"

# VMware: 检查 vmxnet3 驱动是否安装（VM 内执行）
Get-PnpDevice | Where-Object { $_.FriendlyName -match "vmxnet|vmware" }

# 检查 Hyper-V Integration Services 版本
Get-VMIntegrationService -VMName "YourVMName" | Format-Table Name, Enabled, PrimaryStatusDescription

5. 各根因对应解决方案

根因 1: 驱动程序缺失

原因： OEM 驱动未安装，或操作系统升级后 inbox 驱动不支持该网卡。

# 从 INF 文件安装驱动
pnputil /add-driver "C:\Drivers\NetAdapter.inf" /install

# 使用 Windows Update 搜索驱动
# 设备管理器 → 右键未知设备 → 更新驱动程序 → 自动搜索

# 从制造商网站下载驱动后安装
# Intel: https://www.intel.com/content/www/us/en/download-center
# Realtek: https://www.realtek.com/en/downloads
# Broadcom: 通过 OEM（Dell/HP/Lenovo）支持页面下载

根因 2: 适配器被禁用

原因： 管理员手动禁用、组策略禁用、或电源管理自动关闭。

# 启用所有被禁用的网络适配器
Get-NetAdapter -IncludeHidden | Where-Object { $_.Status -eq 'Disabled' } | Enable-NetAdapter

# 检查并禁用电源管理关闭网卡的设置
$adapter = Get-NetAdapter | Select-Object -First 1
$deviceId = (Get-PnpDevice -FriendlyName $adapter.InterfaceDescription).InstanceId
# 然后在设备管理器 → 适配器属性 → 电源管理 → 取消勾选"允许计算机关闭此设备以节省电源"

# 通过注册表禁用电源管理
$regPath = "HKLM:\SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}"
Get-ChildItem $regPath | ForEach-Object {
    $friendlyName = (Get-ItemProperty $_.PSPath).DriverDesc
    if ($friendlyName) {
        Set-ItemProperty $_.PSPath -Name "PnPCapabilities" -Value 24 -Type DWord
        Write-Host "Disabled power management for: $friendlyName"
    }
}

根因 3: 幽灵（Ghost）适配器残留

原因： 旧硬件或旧虚拟适配器的注册信息残留在系统中，可能占用 IP 配置或引起冲突。

:: 显示所有设备（包括非当前连接的）
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
devmgmt.msc
:: 手动在设备管理器中右键灰色的网卡条目 → 卸载设备

:: 使用 pnputil 清理旧驱动
pnputil /enum-devices /class Net /disconnected
pnputil /remove-device "设备实例ID"

根因 4: 物理硬件故障

原因： 网卡硬件损坏、PCIe 插槽问题、或线缆/端口故障。

排查步骤：

  1. 检查网卡 LED 指示灯是否亮起
  2. 将网卡移动到另一个 PCIe 插槽
  3. 将网卡放到另一台机器中测试
  4. 检查 BIOS/UEFI 中是否能看到该设备
  5. 对于板载网卡，检查 BIOS 中 “Onboard LAN” 是否为 Enabled

根因 5: 虚拟机网卡未连接

原因： VM 配置中未添加网络适配器，或虚拟交换机被删除。

# Hyper-V: 添加网络适配器
Add-VMNetworkAdapter -VMName "VM01" -SwitchName "Default Switch"

# Hyper-V: 如果虚拟交换机不存在，先创建
New-VMSwitch -Name "External-Switch" -NetAdapterName "Ethernet" -AllowManagementOS $true

# VMware: 通过 VM Settings GUI 添加 Network Adapter
# 或编辑 .vmx 文件添加:
# ethernet0.present = "TRUE"
# ethernet0.connectionType = "nat"
# ethernet0.virtualDev = "vmxnet3"

根因 6: OS 升级后驱动丢失

原因： In-place upgrade 未迁移 OEM 网卡驱动，或新 OS 版本不支持旧驱动。

# 检查旧驱动是否还在驱动存储中
pnputil /enum-drivers | findstr /i "net"

# 检查 Windows 升级日志中的驱动迁移信息
Get-Content "C:\Windows\Panther\setupact.log" | Select-String -Pattern "driver" -Context 2,2 | Select-Object -First 20

# 检查兼容性报告
Get-Content "$env:SystemDrive\`$WINDOWS.~BT\Sources\Panther\compat*.xml" -ErrorAction SilentlyContinue

# 从旧驱动存储恢复（如果 Windows.old 存在）
# 旧驱动位置: C:\Windows.old\Windows\System32\DriverStore\FileRepository\

根因 7: WMI 仓库损坏

原因： WMI 仓库损坏导致 Windows 无法正确枚举网络设备。

:: 验证 WMI 仓库一致性
winmgmt /verifyrepository

:: 尝试修复 WMI 仓库
winmgmt /salvagerepository

:: 如果修复失败，重置 WMI 仓库（警告：会丢失所有自定义 WMI 数据）
winmgmt /resetrepository

根因 8: 最终手段 — 网络栈完全重置

原因： 当所有其他方法均失败时，使用 netcfg -d 完全重置网络配置。

:: ⚠️ 警告：此命令将移除所有网络适配器和协议绑定，需要重新配置所有网络设置！
netcfg -d

:: 配合以下命令进行完全网络重置
netsh winsock reset
netsh int ip reset
ipconfig /flushdns

:: 重启计算机
shutdown /r /t 0

6. 实用 Tips

Tip 1: 在设备管理器中显示隐藏设备，旧版 Windows 需要先设置环境变量 set DEVMGR_SHOW_NONPRESENT_DEVICES=1，Windows 10 1809+ 可直接在菜单中点击 View → Show hidden devices。

Tip 2: 更新驱动后，建议先 Disable 再 Enable 适配器（而不仅仅是重新安装驱动），这可以确保新驱动被完整加载。

Tip 3: 幽灵网卡（Ghost NIC）可能占用 IP 配置。如果新网卡无法使用旧网卡的 IP 地址，先删除幽灵网卡再配置 IP。

Tip 4: 如果网卡间歇性消失，检查电源管理设置：设备管理器 → 适配器属性 → 电源管理 → 取消勾选 “Allow the computer to turn off this device to save power”。

Tip 5: BIOS/UEFI 中禁用网卡对 Windows 完全不可见，Get-PnpDevice 也不会列出。必须进入 BIOS 检查 “Onboard LAN” 或 “NIC Configuration” 设置。

Tip 6: NIC Teaming (LBFO) 环境中，如果从 Team 中移除物理网卡，Team 适配器本身可能消失。先检查 Team 配置：Get-NetLbfoTeam 和 Get-NetLbfoTeamMember。

Tip 7: 笔记本 Wi-Fi 适配器可能被 飞行模式（Airplane Mode） 或 物理无线开关 隐藏。检查：Get-NetAdapter -Name "Wi-Fi*" -IncludeHidden 以及飞行模式开关状态。

Tip 8: netcfg -d 是网络栈的”核武器级”重置，会移除所有第三方网络协议、过滤驱动和适配器配置。仅在所有其他方法失败后使用，且执行前务必记录当前网络配置。

7. 参考文档

暂无可验证的参考文档。

Scenario Map: TCP/IP — Network Adapter Missing

Product/Service: Windows TCP/IP Stack
Scope: Network adapter is not visible or unusable in the system
Last Updated: 2026-03-11

1. Scenario Overview

Network Adapter Missing refers to a situation where Windows cannot recognize, load, or display one or more network adapters, rendering network connectivity completely unavailable. This scenario covers all adapter types including physical NICs, virtual NICs (Hyper-V / VMware), and Wi-Fi adapters.

Sub-type Classification

mindmap
  root((Network Adapter Missing))
    Adapter not shown in ncpa.cpl
      Network Connections window is empty
      Get-NetAdapter returns nothing
    Device Manager yellow/red icon
      Driver load failure
      Code 31 / Code 10 error
      Resource conflict
    Completely invisible adapter
      Hidden device not shown
      Ghost adapter from old hardware
      PnP enumeration failure
    Adapter shows Disabled
      Disabled by admin or policy
      Disabled by power management
      Disabled by Group Policy
    VM NIC removed or not attached
      Hyper-V vNIC missing
      VMware NIC not present
      VM generation mismatch
    Physical NIC hardware failure
      PCIe slot failure
      NIC LED not lighting up
      NIC not detected in BIOS
    Driver missing after OS upgrade
      In-place upgrade lost OEM driver
      Inbox driver not compatible
      Driver store corrupted

2. Typical Symptoms

# Symptom Impact
1 Opening ncpa.cpl (Network Connections) shows “No network adapters found” or completely blank All network connections unavailable
2 Get-NetAdapter returns empty result with no adapters listed PowerShell network management non-functional
3 Device Manager shows network adapter entry with yellow exclamation (!) or red cross (×) Adapter exists but driver failed to load
4 After OS upgrade (e.g., Win10→Win11), NIC driver is missing No network after upgrade
5 Hyper-V / VMware VM has no NIC visible VM has no network connectivity
6 Adapter shows “Network cable unplugged” but was previously working fine Intermittent or permanent disconnection
7 ipconfig /all produces no adapter information output No IP address, DNS unavailable
8 System tray network icon shows red cross with “No connections available” User cannot connect to any network

3. Troubleshooting Flowchart

flowchart TD
    A["🔍 Start: Network Adapter Not Visible"] --> B{"Open Device Manager<br/>devmgmt.msc"}
    
    B -->|"NIC listed with<br/>yellow ! icon"| C["Check driver status<br/>Right-click → Properties"]
    B -->|"NIC listed but<br/>shows Disabled"| D["Right-click → Enable Device<br/>or: Enable-NetAdapter -Name *"]
    B -->|"NIC NOT listed<br/>at all"| E{"View → Show Hidden Devices<br/>set DEVMGR_SHOW_NONPRESENT_DEVICES=1"}
    
    C --> C1{"Driver error code?"}
    C1 -->|"Code 10/31:<br/>Cannot start"| C2["Uninstall driver completely<br/>pnputil /delete-driver oemXX.inf /uninstall<br/>Then: Scan for hardware changes"]
    C1 -->|"Code 28:<br/>No driver installed"| C3["Download driver from OEM website<br/>or: pnputil /add-driver driver.inf /install"]
    C1 -->|"Code 39/41:<br/>Driver corrupted"| C4["sfc /scannow<br/>DISM /Online /Cleanup-Image /RestoreHealth<br/>Then reinstall driver"]
    
    D --> D1{"Adapter appears<br/>in ncpa.cpl?"}
    D1 -->|"Yes"| D2["✅ Resolved: Adapter was disabled"]
    D1 -->|"No"| D3["Check Group Policy:<br/>gpedit.msc → Network Connections<br/>Check if adapter is hidden by policy"]
    
    E -->|"Ghost adapter found<br/>(grayed out)"| F["Right-click → Uninstall Device<br/>Remove ghost NIC<br/>Reboot and rescan"]
    E -->|"Still no adapter<br/>found"| G{"Check BIOS/UEFI Settings"}
    
    G -->|"NIC is Disabled<br/>in BIOS"| H["Enable NIC in BIOS<br/>Save settings and reboot"]
    G -->|"NIC is Enabled<br/>in BIOS"| I{"Physical or Virtual?"}
    
    I -->|"Physical Machine"| J["Check hardware:<br/>1. Reseat NIC in PCIe slot<br/>2. Try different PCIe slot<br/>3. Check NIC LED indicators<br/>4. Test NIC in another machine"]
    I -->|"Virtual Machine"| K{"Check VM Settings"}
    
    K -->|"Hyper-V"| K1["Hyper-V Manager → VM Settings<br/>Add Hardware → Network Adapter<br/>Select virtual switch"]
    K -->|"VMware"| K2["VM Settings → Add → Network Adapter<br/>Select network type:<br/>Bridged / NAT / Host-Only"]
    
    J --> J1{"NIC works in<br/>another machine?"}
    J1 -->|"Yes"| J2["Motherboard PCIe slot issue<br/>or: OS driver/registry corruption<br/>Try: netcfg -d (nuclear reset)"]
    J1 -->|"No"| J3["🔴 Hardware Failure<br/>Replace NIC"]
    
    C2 --> Z{"Adapter working<br/>after fix?"}
    C3 --> Z
    C4 --> Z
    F --> Z
    H --> Z
    K1 --> Z
    K2 --> Z
    
    Z -->|"Yes"| Z1["✅ Resolved"]
    Z -->|"No"| Z2["Nuclear Reset Options:<br/>1. netcfg -d<br/>2. netsh winsock reset<br/>3. WMI rebuild:<br/>winmgmt /resetrepository"]
    
    Z2 --> Z3{"Resolved after<br/>nuclear reset?"}
    Z3 -->|"Yes"| Z4["✅ Resolved after reset"]
    Z3 -->|"No"| Z5["🔴 Consider OS repair install<br/>or hardware replacement"]

4. Detailed Troubleshooting Steps and Commands

Step 1: Check Basic Adapter Status

# List all network adapters (including hidden ones)
Get-NetAdapter -IncludeHidden

# List all PnP devices in the Net class (including problematic devices)
Get-PnpDevice -Class Net

# Use pnputil to enumerate all network class devices
pnputil /enum-devices /class Net

# List all network adapters with details (WMI)
Get-WmiObject Win32_NetworkAdapter | Format-Table Name, NetConnectionStatus, PNPDeviceID -AutoSize

# List all network adapter configurations
Get-WmiObject Win32_NetworkAdapterConfiguration | Where-Object { $_.IPEnabled } | Format-List Description, IPAddress, DHCPEnabled

Step 2: Check Driver Status

# List all installed network drivers
dism /online /get-drivers /all | findstr /i "net"

# Check network driver INF files in the driver store
pnputil /enum-drivers | findstr /i "net"

# View driver details for a specific device
Get-PnpDeviceProperty -InstanceId "PCI\VEN_8086*" | Format-Table KeyName, Data -AutoSize

# Check driver signing status
sigverif  # GUI tool
# or
driverquery /v | findstr /i "network"

Step 3: Show Hidden Devices in Device Manager

:: Method 1: Set environment variable then open Device Manager
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
devmgmt.msc

:: Method 2: PowerShell approach
[Environment]::SetEnvironmentVariable("DEVMGR_SHOW_NONPRESENT_DEVICES", "1", "Process")
Start-Process devmgmt.msc

Step 4: Check Core Network Services

# Check NDIS (Network Driver Interface Specification) service status
sc query NDIS

# Check Network Connections service
sc query Netman

# Check Network Store Interface service
sc query nsi

# Check WLAN AutoConfig (required for Wi-Fi adapters)
sc query WlanSvc

# Check all network-related services
Get-Service | Where-Object { $_.DisplayName -match "network|ndis|wlan|net" } | Format-Table Name, Status, StartType -AutoSize

Step 5: Check Event Logs

# View NIC-related system event logs (last 24 hours)
Get-WinEvent -FilterHashtable @{
    LogName = 'System'
    ProviderName = 'ndis', 'NetBT', 'Tcpip', 'e1iexpress', 'NETVSC'
    StartTime = (Get-Date).AddHours(-24)
} -ErrorAction SilentlyContinue | Format-Table TimeCreated, Id, LevelDisplayName, Message -Wrap

# View PnP-related events (device installation/removal)
Get-WinEvent -FilterHashtable @{
    LogName = 'System'
    ProviderName = 'Microsoft-Windows-Kernel-PnP'
    StartTime = (Get-Date).AddHours(-24)
} -ErrorAction SilentlyContinue | Select-Object -First 20 | Format-Table TimeCreated, Id, Message -Wrap

# View Device Setup Manager log
Get-WinEvent -LogName 'Microsoft-Windows-DeviceSetupManager/Admin' -MaxEvents 20 -ErrorAction SilentlyContinue | Format-Table TimeCreated, Message -Wrap

Step 6: BIOS/Firmware and Hardware Checks

# Check if the system recognizes the NIC PCI device
Get-PnpDevice -Class Net -Status OK, Error, Degraded, Unknown | Format-Table FriendlyName, Status, InstanceId -AutoSize

# Check for network devices on the PCI bus
Get-PnpDevice | Where-Object { $_.InstanceId -match "PCI\\VEN" -and $_.Class -eq "Net" }

# View NIC hardware IDs (visible even if driver is not loaded)
pnputil /enum-devices /class Net /drivers

Step 7: Virtual Machine Specific Checks

# Hyper-V: Check VM network adapter configuration
Get-VMNetworkAdapter -VMName "YourVMName"

# Hyper-V: List all virtual switches
Get-VMSwitch

# Hyper-V: Add a network adapter to a VM
Add-VMNetworkAdapter -VMName "YourVMName" -SwitchName "YourSwitch"

# VMware: Check if vmxnet3 driver is installed (run inside VM)
Get-PnpDevice | Where-Object { $_.FriendlyName -match "vmxnet|vmware" }

# Check Hyper-V Integration Services version
Get-VMIntegrationService -VMName "YourVMName" | Format-Table Name, Enabled, PrimaryStatusDescription

5. Solutions by Root Cause

Root Cause 1: Driver Missing

Cause: OEM driver not installed, or inbox driver does not support the NIC after an OS upgrade.

# Install driver from INF file
pnputil /add-driver "C:\Drivers\NetAdapter.inf" /install

# Use Windows Update to search for driver
# Device Manager → Right-click unknown device → Update driver → Search automatically

# Download driver from manufacturer website and install
# Intel: https://www.intel.com/content/www/us/en/download-center
# Realtek: https://www.realtek.com/en/downloads
# Broadcom: Via OEM (Dell/HP/Lenovo) support page

Root Cause 2: Adapter Disabled

Cause: Manually disabled by admin, disabled by Group Policy, or turned off by power management.

# Enable all disabled network adapters
Get-NetAdapter -IncludeHidden | Where-Object { $_.Status -eq 'Disabled' } | Enable-NetAdapter

# Check and disable power management setting that turns off NIC
$adapter = Get-NetAdapter | Select-Object -First 1
$deviceId = (Get-PnpDevice -FriendlyName $adapter.InterfaceDescription).InstanceId
# Then in Device Manager → Adapter Properties → Power Management → Uncheck "Allow the computer to turn off this device to save power"

# Disable power management via registry
$regPath = "HKLM:\SYSTEM\CurrentControlSet\Control\Class\{4d36e972-e325-11ce-bfc1-08002be10318}"
Get-ChildItem $regPath | ForEach-Object {
    $friendlyName = (Get-ItemProperty $_.PSPath).DriverDesc
    if ($friendlyName) {
        Set-ItemProperty $_.PSPath -Name "PnPCapabilities" -Value 24 -Type DWord
        Write-Host "Disabled power management for: $friendlyName"
    }
}

Root Cause 3: Ghost Adapter Residue

Cause: Registry entries from old hardware or old virtual adapters remain in the system, potentially occupying IP configurations or causing conflicts.

:: Show all devices (including non-present ones)
set DEVMGR_SHOW_NONPRESENT_DEVICES=1
devmgmt.msc
:: Manually right-click grayed-out NIC entries in Device Manager → Uninstall device

:: Use pnputil to clean up old drivers
pnputil /enum-devices /class Net /disconnected
pnputil /remove-device "DeviceInstanceID"

Root Cause 4: Physical Hardware Failure

Cause: NIC hardware is damaged, PCIe slot issue, or cable/port failure.

Troubleshooting Steps:

  1. Check if NIC LED indicators are lit
  2. Move the NIC to a different PCIe slot
  3. Test the NIC in another machine
  4. Check if the device is visible in BIOS/UEFI
  5. For onboard NICs, verify “Onboard LAN” is set to Enabled in BIOS

Root Cause 5: VM NIC Not Attached

Cause: Network adapter not added in VM configuration, or virtual switch has been deleted.

# Hyper-V: Add a network adapter
Add-VMNetworkAdapter -VMName "VM01" -SwitchName "Default Switch"

# Hyper-V: If virtual switch doesn't exist, create one first
New-VMSwitch -Name "External-Switch" -NetAdapterName "Ethernet" -AllowManagementOS $true

# VMware: Add Network Adapter via VM Settings GUI
# Or edit the .vmx file to add:
# ethernet0.present = "TRUE"
# ethernet0.connectionType = "nat"
# ethernet0.virtualDev = "vmxnet3"

Root Cause 6: Driver Lost After OS Upgrade

Cause: In-place upgrade did not migrate the OEM NIC driver, or the new OS version does not support the old driver.

# Check if old drivers are still in the driver store
pnputil /enum-drivers | findstr /i "net"

# Check Windows upgrade logs for driver migration information
Get-Content "C:\Windows\Panther\setupact.log" | Select-String -Pattern "driver" -Context 2,2 | Select-Object -First 20

# Check compatibility report
Get-Content "$env:SystemDrive\`$WINDOWS.~BT\Sources\Panther\compat*.xml" -ErrorAction SilentlyContinue

# Recover from old driver store (if Windows.old exists)
# Old driver location: C:\Windows.old\Windows\System32\DriverStore\FileRepository\

Root Cause 7: WMI Repository Corruption

Cause: Corrupted WMI repository prevents Windows from properly enumerating network devices.

:: Verify WMI repository consistency
winmgmt /verifyrepository

:: Attempt to repair WMI repository
winmgmt /salvagerepository

:: If repair fails, reset WMI repository (WARNING: loses all custom WMI data)
winmgmt /resetrepository

Root Cause 8: Last Resort — Full Network Stack Reset

Cause: When all other methods have failed, use netcfg -d to completely reset network configuration.

:: ⚠️ WARNING: This command removes ALL network adapters and protocol bindings. All network settings must be reconfigured!
netcfg -d

:: Combine with the following commands for a complete network reset
netsh winsock reset
netsh int ip reset
ipconfig /flushdns

:: Reboot the computer
shutdown /r /t 0

6. Practical Tips

Tip 1: To show hidden devices in Device Manager, older Windows versions require setting the environment variable set DEVMGR_SHOW_NONPRESENT_DEVICES=1 first. Windows 10 1809+ supports clicking View → Show hidden devices directly from the menu.

Tip 2: After updating a driver, it is recommended to Disable then Enable the adapter (not just reinstall the driver). This ensures the new driver is fully loaded.

Tip 3: Ghost NICs may occupy IP configurations. If a new NIC cannot use the old NIC’s IP address, remove the ghost NIC first before configuring the IP.

Tip 4: If a NIC disappears intermittently, check power management settings: Device Manager → Adapter Properties → Power Management → Uncheck “Allow the computer to turn off this device to save power”.

Tip 5: A NIC disabled in BIOS/UEFI is completely invisible to Windows — Get-PnpDevice will not list it. You must enter BIOS to check the “Onboard LAN” or “NIC Configuration” setting.

Tip 6: In NIC Teaming (LBFO) environments, if a physical NIC is removed from the team, the team adapter itself may disappear. Check team configuration first: Get-NetLbfoTeam and Get-NetLbfoTeamMember.

Tip 7: Laptop Wi-Fi adapters may be hidden by Airplane Mode or a physical wireless switch. Check with: Get-NetAdapter -Name "Wi-Fi*" -IncludeHidden and verify the Airplane Mode toggle status.

Tip 8: netcfg -d is the “nuclear option” for the network stack — it removes all third-party network protocols, filter drivers, and adapter configurations. Use only after all other methods have failed, and always document the current network configuration before executing.

7. References

No verified reference documents available at this time.