I was trying to do a system restore and when it was just initializing, the power went out and the PC got shut down. When the power came back on, the PC booted up, but it took longer than usual and when I tried to log in, it got stuck at the welcome screen and was like that for a very long time so I had to shut it down. When I tried to access the advanced system settings by holding shift and pressing restart, all it booted up to was a grey screen with a mouse pointer. I have tried to press f8 when booting up but nothing has worked so far. My PC came with windows 8 pro but I just recently upgraded to 8.1. But it didn't come with a recovery CD so I can't do any thing about it. What i do have is a old windows 7 home premium install cd. Can i do something about it? Can someone please help? I really need the PC up and running by tomorrow because I need to do a lot of college work on it and all my files are saved on there. Please help!?