My Acer Aspire 6920g

Hello,
My Acer Aspire 6920g wont load.
It can get to like the safe mode option screen. I try going into safe mode and it does the load list thingy and then just black screen. I can leave it for hours and hours on the black screen but it just doesnt go anywhere.
I cant do a factory restore as the same thing happens.
Does anyone have any ideas on how I can fix this.
I wasnt given a vista home premium disk when I brought the laptop and now i am at the end of my rope.
I have run out of things that i can try apart from reformatting the drive and trying a different Operating system on it but im not even sure if this will work.
PLEASE HELP ME