what could be the problem?

[Simplicity]

OK, so i have my old laptop that i use alot and about a year ago my xp media center edition just started to fail, so i got windows 7, and now about a year later i turn on my laptop and it gives me two options to boot normally or in repair mode. so if i boot in repair mode it will look like it is working then just go to a blank screen. Now if i boot normally it will blue screen right away. So now i tryed to reinstall win 7 and it just goes to a black screen and does nothing.