Have you tried last known good configuration yet? What version of Windows are you running?

Try what rapture posted then go to Start - Run Type Msconfig go to startup tab uncheck anything you don't need running like quick time,word and such if not for sure check this site.

http://homecomputerrepaironline.com/...artlist_c.html

How much Memory you got on that Machine?

Also might want to check the manufactures site for a BIOS upgrade.

That can be caused by number of things.

1. Corrupted registry.
2. Corrupted files. (system or programs)
3. Dying hardware (HD, RAM, Mobo...)

You should try booting in safe mode (press and hold f8 while booting) and look in your event viewer (in "administrative tools" <- might be that you would have to check the "display administrative tools" in Start/settings/taskbar and start menu/start menu/customize). In the event viewer look for the entries with the time-stamp of your latest failed boot attempt, and look for the errors and/or alerts. If any, please post them.

Also, while you're at it, look in Control panel/system/hardware/device manager, and if any of the listed devices are marked with red cross (disabled) or yellow triangle (not started), please post that too.

Oh, yeah, Your hardware specs, please...

hi,
if you're running win XP try to visit this site, to recover from a corrupt registry.. http://support.microsoft.com/kb/307545