Windows 2008 is showing error  “An unauthorized change was made to Windows” and unable to login to Administrator account, it shows “Preparing your desktop”.

Error Code: 0xC004D401

The security processor reported a file mismatch error.

How to solve 0xC004D401 – An unauthorized change was made to Windows Server 2008?

  • Scan your system using Microsoft Safety Scanner
  • Reboot the system.
  • Disable the Antivirus temporarily.
  • Go to %windir%\System32 folder (C:\Windows\System32)
  • Locate cmd.exe
  • Right-click on cmd.exe and select Run as Administrator
  • Enter this command given below and press enter key.
cscript %windir%\System32\slmgr.vbs /ilc %windir%\System32\licensing\ppdlic\Security-Licensing-SLC-ppdlic.xrm-ms
  • Reboot the computer two times.

(NB: Hard boot if you are unable to reboot normally, take all precautions before hard boot)

Scan and repair Windows system files using SFC

Run System File Checker tool (SFC) command will help you scan and repair missing or corrupted system files.

Open command prompt as administrator and run SFC /scannow command

C:\Windows\system32>sfc /scannow
Scan your system files for corruption- Fix Corrupted System Files
SFC Scan

Run DISM (Deployment Image Servicing and Management) tool

Open Command prompt (cmd.exe) as administrator, type this DISM command given below and press enter key.

DISM.exe /Online /Cleanup-image /Restorehealth

DISM will scan and identify the corrupted files, then it will try to replace the corrupted files by downloading new files through Windows Update process. It will take several minutes to complete the whole process. If the Windows update client is already corrupted then you may have to download the latest System Update Readiness Tool and install it to fix corrupted files. Make sure you reliable have internet connection.