You could try to perform a manual system restore if you are really desperate
Do as follows:
1. Boot to the Windows Recovery Environment and select the Command Prompt
2. At the prompt enter the following commands:
cd windows\system32\config
3. At the prompt cd windows\system32\config> enter the following:
ren default default.old
ren sam sam.old
ren system system.old
ren security security.old
ren software software.old
cd regback
4. At the prompt C:\windows\system32\config\regback> enter the following:
copy default c:\windows\system32\config
copy sam c:\windows\system32\config
copy system c:\windows\system32\config
copy security c:\windows\system32\config
copy software c:\windows\system32\config
5. Close the command prompt window and reboot the computer