You do these commands below blindly but it will works if you follow them exactly:
1) Restart your PC
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.