I have a compaq presario 2500 windows xp home edition laptop and I cant get past

Hello,
I have a compaq presario 2500 windows xp home edition laptop and I cant get past the blue screen with windows logo..This laptop worked fine,and I don't have the recovery cd's to do a recovery on it,so I pressed some of the f keys to try and find a full system recovery on it,but no success.This laptop was given to me so I wanted to put it back to factory settings.But now all I get is the blue screen with windows xp logo.How do I get it to come back on.I've tried everything I can think of.Even tried safe mode.Tried to reset it from the back.Took battery out.Pressed on button fer 15/30 seconds then turned back on...NOTHING!..So what can I do to get it on...Please help..Thank you so very much.
Sincerely,
Ole Sal