My computer will start up and ask if I want to run in safe mode or start windows normally, no matter what way I choose to start the computer it will make it to the log in screen and last about 5 seconds before it completely freezes

Symptoms: When you start your computer, you get the black screen with a menu that tells you to start in safe mode, normal mode, etc. When you make a choice, you end up in the same place.

Solution: If you have Windows XP, you'll need an installation disk. Doesn't matter if it's yours or not. You just need a Windows XP disk. Any flavor. Put it in the CD drive and start your computer. Be sure the computer boots from the CD.
You will see the Windows installation message and the first question you will be asked is if you wish to repair Windows or install it. Choose "r" for repair. You will now be presented with a black screen that asks you which version of Windows do you wish to repair. Choose the one that is probably the first on the list--it should just say Windows. It may appear like this: C:\Windows.
You may get a second screen asking for the password. This is the password for the Administrator account. If there is not a password on this account, just hit "enter."
When you get to the C:\> prompt, type CHKDSK /P and let it run. It will most likely find errors and fix them. Once it's finished, Windows should start normally.
If it doesn't, you'll need to check out my link that addresses the "secondary fix."