My daughters advent laptop running windows vista home edition won't complete startup?

It has worked for well over a year, now when she switches on the machine goes through to startup screen and sits on "please wait" then display flicks black a few times and back to "please wait".. I've tried system restore and various repair options from f8 screen with no success. Also tried safe mode and just get a black screen with safe mode written in four corners and the version on top(is this normal?). I can access internet from there by using task manager but not alot else. any help greatly appreciated