Black Screen in Vista

Hello,
Dell Inspiron, Vista. After a re-start I now have a black screen with white cursor. Nothing seems to have any affect. I've tried every form of safe mode restart. When I hit the shift key 5 times, I hear a chirp but the black screen reamins.
I goes through all the screens (Dell, then Microsoft Windows with the moving bar) and it sounds like a regular start-up, then I get he black screen. I've tried the Repair Computer option (from the F8 menu), select my user id and p/w, select System Restore but it tell sme there are no restore points.
When I select "Windows Complete PC Restore" it tells me it cannot find a backup on this computer.
I can go to command prompt, but I don't know what command prompt to type in.(I can actually pull up Notepad from there)
I am at a loss as what to do from here. I 've tried the restore CD, but I can't even see that menu without the desktop comming up.
Need help - thanks