Windows hangs right before login screen

I have a Dell Inspiron 1420 running Windows Vista. When I turn it on, it displays the green bar and "(c) Microsoft Corporation" like normal. After that, however, it goes to a black screen and the only thing I see is the mouse, which I can move around. It remains this way as long as it is turned on and never actually gets to the login screen. Even when I boot into safe mode, it does the exact same thing.

I tried booting my computer from the OS CD and selecting "Repair your computer."
1. Startup Repair: returns the message "Startup repair could not detect a problem."
2. System Restore: I select a restore point and wait, but it always fails.

The thing is I don't want to lose any data, so reformatting the HD or reinstalling Windows is not an option. There must be a way to fix the bad Windows files that are not allowing my computer to reach the login screen.

 

I had that problem yesterday. I tried to get into the OS using safe mode, the system restore and the dvd dell gave me. I couldn't get in and i did the diagnostic test from bootup and it looked like my hard drive died. Dell sending me a new one today to replace mine.

 

You could try Virus/Spyware scans with a bootable CD, or pull your drive and backup the data to another computer before formating.

 

My hard drive is just fine. And I just did a virus scan a few days ago.

I think the problem is being caused by a faulty driver that Windows Update installed -- but I don't know how to fix it.

 

do you know where I can get such a cd? i have the same blank logon screen and suspect its a virus.