If you can't get it to boot into safe mode you are probably screwed.
What model is it, some of these netbooks don't even have a proper hard disk.
If you go into the bios, is there a disk checker option, proper laptops have them but netbooks might not. If there is run it and see if there are errors.
Seen any S.M.A.R.T errors over the last week or so on boot up?
Do you need to get any data off of it before you restore it. if so the ultimate windows boot cd is a godsend:- http://www.ubcd4win.com/index.htm
you will need another computer and a copy of windows to create the cd though. If you can't do that then the linux equivalent (http://www.ultimatebootcd.com/
) is also good but a bit more complicated.