No XP Logon Prompt

I’m hoping to get answers from pros here… This is ridiculous…

My computer boots up fine without any errors. After the normal XP loading screen, however, logon prompt is nowhere to be found. ctrl-alt-delete didn’t work although I can hover the screen with my mouse pointer. My computer was working fine last night, but suddenly today, when I booted up the computer this keeps on happening. Strange thing is same thing happens for safe mode.

I’m on my secondary computer (older) to post this. I’ve been looking up online but there are no answers to be found… I have too many important files on the computer for a format - not until I can make backups but I can’t without getting into XP first.

Last few things I did last night are - I installed a new security update from MS (I think it was a patch for Windows Meta File (WMF) vulnerability) and I also browsed m90.org for a good hour.

I wonder if anyone had similar issues before… any input would be appreciated. Thanx.