If (and ONLY if) you are Ok with editing the registry you could try this, but please don't blame me if you screw the PC up worse.
1.
Open the Registry Editor (Start - Run - regedit) and check the following:
HKEY_LOCAL_MACHINE/Software/Microsoft/Windows NT/Current Version/Winlogon
The parameter Userinit in the right window should have the following value
C:\WINDOWS\system32\userinit.exe.
Any additions should be deleted.
2.
Delete the following key:
HKEY_CURRENT_USER/Software/Microsoft/Windows/Current Version/Explorer/MountPoints2.
This step should be repeated for ALL users on the computer including the built-in Administrator account.
3.
Reboot the computer