Windows 7 black screen with curser?

Hello, I was using my computer yesterday, plugged in a usb and began to notice some strange things. Firstly, my computer began to lag really badly, so much that it took over 2 minutes just to open a word document. So then i decided to restart the computer. It did its normal thing but after the windows loading animation, instead of showing the log in screen, i see a black screen and cursor. I tried to find a solution; system restore, safe mode, taking out the usb , none of them seemed to work. I really need the files on my computer so please help.

p.s ctrl+alt+delete does't work on the black screen
p.p.s In safe mode, when it's loading drivers, it stops after having loaded "avgidseh", I don't think its this drivers problem but maybe the one after.