Windows 2000 loader error 3?

when i power on my dell laptop and it goes to the starting up thing (black screen w/ white letters) it stops and says "windows 2000 could not start because of an error in the software.....please report this problem as loader error 3. Please tell me what it is that I need to do in order to get back up and running on my laptop...also, I don't know hardly anything about computers or the lingo so please explain step by step in terms I can understand. I really appreciate it! I need to get on my comp ASAP....if you can help me out you'll be SUCH a lifesaver!!!