I have a dell inspiron PC running Windows XP (pity me). The laptop is about 1 year old. Today my screen went (almost) totally dark....but the OS didn't crash. Why?

I know this is really hard to troubleshoot….I know there was no OS crash because I could still just barely see what was going on…enough to close and save and restart. Problem solved…until 6 hours later. Rinse and repeat. Is this probably a hardware problem with the display?