Whats wrong with my computer dammit!?! PLEASE HELP!?

okay so my computers been recently having viruses and ive had to restore it a couple times. for instance i came home one day and it just wouldn't start, plain and simple, wouldn't even let me restore it so i had to use a virtual drive to restore it from a back up. and then when i did that it crashed again so i restored and now this is my 3rd restore in a couple months and a new problem has emerged. sometimes when my computer, well most times when my computer starts or when i shut down a game or window it goes to a white screen. and it stays there and i can see the shades in the background but i cant see anything clearly at all. i usually just play with the ons on the monitor because that seems to work after i let it sit like that for a bit. i thought it was i just had to clean the video card so i did and it dint work and sometimes it will randomly do it also and my computer will just shut down and ill start it and the white screen will come up and i cant get it off so i justy say screw it. any ideas on how to fix this? THANKS!