Firstly, there appears to be many causes of the black screen issue. The symptoms are very distinctive and troublesome. After starting your Windows 7, Vista, XP, NT, W2K, W2K3 or W2K8 PC or server the system appears normal. However, after logging on there is no desktop, task bar, system tray or side bar. Instead you are left with a totally black screen and a single My Computer Explorer window. Even this window might be minimized making it hard to see.
If we have these symptoms try free Black Screen Fix. It will fix the most common causes of this issue. Running the fix program is easy under normal circumstances, simply download with browser using the link above and run the program. However trying to do this from the PC which has the black screen it is a bit more tricky. In these circumstances follow the procedure below:
1) Restart PC
2) Logon and wait for the black screen to appear
3) Make sure that PC is 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 we 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 the 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 PC and the black screen problem will hopefully be gone.
Source for the fix is here.