Windows 2000 and XP include a feature called Windows File Protection (WFP), part of the System File Checker, which is intended to avoid some of the common DLL consistency issues. This feature may also block valid attempts to change system files and it can therefore be disabled using this tweak.
Open your registry and find the key below.
Change the value of "SFCDisable" to equal "ffffff9d" to disable WFS or "0" to enable it. The other valid hexadecimal values are:
ffffff9d - for completely disabled
Restart Windows for the change to take effect.
Additional Steps for Windows 2000 Service Pack 2 and Windows XP
This setting is disabled in Windows 2000 SP2 and Windows XP, and needs to re-enabled using a hex editor and changing SFC.DLL (or SFC_OS.DLL for Windows XP) following these instructions:
Windows 2000 SP2
- Make a backup the SFC.DLL in the C:\WINNT\SYSTEM32 directory.
- Make an additional copy of SFC.DLL called SFC1.DLL and open it in a hex editor.
- At offset 00006211 (6211h) you should find the values "8B" and "C6". Do not continue if you are unable to find these values.
- Change the values "8B C6" to read "90 90" and save the changes.
- Run these commands to update the system files:
copy c:\winnt\system32\sfc1.dll c:\winnt\system32\sfc.dll /y
copy c:\winnt\system32\sfc1.dll c:\winnt\system32\dllcache\sfc.dll /y - If you are prompted to insert the Windows CD, click Cancel.
- Restart Windows for the change to take effect.
- Make a backup the SFC_OS.DLL in the C:\WINDOWS\SYSTEM32 directory.
- Make an additional copy of SFC_OS.DLL called SFC_OS1.DLL and open it in a hex editor.
- Windows XP (no Service Pack)
At offset 0000E2B8 (0E2B8h) you should find the values "8B" and "C6".
Windows XP (Service Pack 1)
At offset 0000E3BB (0E3BBh) you should find the values "8B" and "C6". - Do not continue if you are unable to find these values.
- Change the values "8B C6" to read "90 90" and save the changes.
- Run these commands to update the system files:
copy c:\windows\system32\sfc_os1.dll c:\windows\system32\sfc_os.dll /y
copy c:\windows\system32\sfc_os1.dll c:\windows\system32\dllcache\sfc_os.dll /y - If you are prompted to insert the Windows CD, click Cancel.
- Restart Windows for the change to take effect.
Note : You must manually modify the operating system files using a hex editor to allow this tweak to disable SFC on Windows 2000 (SP1+) or Windows XP.
Registry Settings |
System Key : [HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft \Windows NT\CurrentVersion\Winlogon] Value Name : SFCDisable Data Type : REG_DWORD (DWORD Value) Value Data : 0 = enabled (default), ffffff9d = disabled |
Disclaimer : Modifying the registry can cause serious problems that may require you to reinstall your operating system. We cannot guarantee that problems resulting from modifications to the registry can be solved. Use the information provided at your own risk.