Virus alert? Pop-ups? C: says nothing’s there? Desktop icons gone? Start Menu is empty?
Yeah, you got something nasty.
Boot into safe mode, fire up a cmd.exe/DOS box & let’s ‘attrib’ your files back to normal:
attrib -s -h c:*.* /S /D
Install the app, run the updates & do a full scan.
Can’t run task manager?
.... delete the key for "DisableTaskMgr"
Security Center says Automatic Updates is off?
Start -> Run -> regsvr32 wuaueng.dll
More to come, as I try to keep this going.