If you have another computer, download and burn
Hiren's Boot CD.
Put that in your laptop and boot from it. Run the Memtest 86+
If it comes back with any errors, you have bad ram. You can try taking out one stick, repeating, until you find out which stick(s) is bad.
If you can't do that, get a cheap 2.5" external hard drive enclosure, slap your hard drive in there, and copy any files you want to another location (not on the same drive). (Typically "C:/Documents and Settings/[username]/" is a good directory that will get most of you media and a lot of savegames.)
You can then put your hard drive back in, reinstall windows/use your recovery disk and bring you laptop back to life. Copy your files back over and you should be set.