Weird Gray screen right after welcome screen

Hey all,

I've been experiencing a strange problem all of a sudden. When I started my PC this morning, it went on to the blue welcome screen and then suddenly a gray-black screen appears and stays there for a long time. eventually, multiple instances of the same error message pop up with multiple processes:

the instruction at 0x referenced memory at 0x. The required data was not placed into memory because I/o error....

Upon restarting, I've tried safe mode, repair, last config etc. to no avail. Windows also tries to check c: for errors sometimes, but it just hangs saying some unexpected error was found.

I'm at a loss, what to do! please help guys. Thanks

Anything in the Event Viewer?

I would probably try to update or replace the video drivers. Have you loaded any programs that might effect it lately?

Run any virus scans lately?