Windows 11下所有VPN无法连接，设备管理器提示(Code 56) Windows is still setting up the class configuration for this device的解决方法咨询

Hey there, let's work through this frustrating VPN Code 56 issue together. This is a typical Windows configuration hiccup, so here are several targeted fixes you can try one by one:

• 重置远程访问服务与相关注册表项
  This operation resets core services VPN relies on and clears restrictions that might block configuration:

  1. Right-click the Start menu, select "Windows Terminal (Admin)" (or Command Prompt as Administrator)
  2. Enter and execute these commands one by one:

     net stop rasman
     net stop remoteaccess
     reg delete HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\RasMan\Parameters /v ProhibitIpSec /f
     net start rasman
     net start remoteaccess
     

  3. Restart your computer after execution, then try connecting to VPN again.

• 修复系统核心文件
  Corrupted system files can cause device class configuration to get stuck—use Windows built-in tools to fix this:

  1. Open the admin terminal, first run:

     sfc /scannow
     

  2. Wait for the scan and repair to finish, then run:

     DISM /Online /Cleanup-Image /RestoreHealth
     

  3. Restart your system after both commands are done, then test the VPN connection.

• 调整VPN设备的注册表配置
  Manually modify the registry to force completion of device class configuration:

  1. Open Device Manager, find the VPN driver with a yellow exclamation mark, right-click and select "Properties"
  2. Switch to the "Details" tab, select "Device Instance Path" from the property dropdown menu, and copy the full path
  3. Press Win+R, enter regedit to open Registry Editor, navigate to:

     HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Enum\<the copied device instance path>\Device Parameters
     

  4. Right-click in the blank space on the right, select "New -> DWORD (32-bit) Value", name it ClassUpperFilters, set its value data to 0
  5. Restart your computer and try connecting to VPN again.

• Disable Fast Startup
  Fast Startup can sometimes cause incomplete initialization of device drivers—try turning it off:

  1. Open Control Panel, go to "Power Options -> Choose what the power buttons do"
  2. Click "Change settings that are currently unavailable", uncheck "Turn on fast startup (recommended)"
  3. Click "Save changes", restart your computer and test the VPN.

If none of the above methods work, try creating a new local administrator account, log in with the new account and test the VPN—corrupted configuration files in your current account might also cause this kind of driver configuration issue.

备注：内容来源于stack exchange，提问作者DirectMaker