This can affect users of Windows 7, Vista, XP, NT, Windows 2000, Windows 2003 or Windows 2008.
There are a few genuine fixes available, and millions of sites offering a fix as an excuse to download or install malicious software.
If you are affected I have a couple of suggestions:
- Restore your computer to the 'Last Known Good Configuration" by accessing the system restore boot options. To do this press the F8 button repeatedly immediately after switching it on - then select the "Last Known Good Configuration" option. This should restore your previous registry settings on the next boot.
- If that doesn't work try this (courtesy of the good people at Prevx)
1) Restart your PCThe cause? It is believed to be an update issued by Microsoft in the last two weeks that appears to erroneously reset the security on the program that loads your desktop, making it invalid. Microsoft are reported by the BBC as investigating the causes, and have officially denied via Technet that their updates are to blame - pointing the finger at 'Malware'.
2) Logon and wait for the black screen to appear
3) Make sure your PC should be able to connect to the internet (black screen does not appear to affect this)
4) Press the CTRL, ALT and DEL keys simultaneously
5) When prompted, Click Start Task Manager
6) In Task Manager Click on the Application Tab
7) Next Click New Task
8) Now enter the command:
"C:\Program Files\Internet Explorer\iexplore.exe" "http://info.prevx.com/download.asp?GRAB=BLACKSCREENFIX"
Note this command assumes that you are using internet explorer as your browser, if not substitute your browser path and file details for those of iexplore.exe or use the Browser option of Task manager to locate it.
9) Click OK and your browser should start up and begin the download process
10) When prompted for the download Click run, the black screen fix program will download and run to automatically fix the issue.
11) Now restart your PC and the black screen problem will hopefully be gone.
I'm expecting a busy few days myself; but hey if they didn't go wrong I would be much the poorer.
I think i'll start recommending Apple Macs - and if you do own any Microsoft shares...
Update 2nd December 13:00 - Microsoft are denying responsibility, but reports are increasing. I've run one of the updates alleged to be the cause without ill effect on a test Windows XP PC - but have received another call from a client. If I get to the bottom of the problem I'll update this article.