By Pressing the F Combination keys you mean tried to go into safe mode or last good known config?
Have U tried like this:
Hold (F8) at startup >the menu will appear :
Last good known config
Bla, bla, bla...
And the Disable auto restart option
None of them work? Or you can't get to them?
Doesn't even the last one work? Don't U get a blue error screen of the actual error with the last option?
Do you have a Win xp cd?