Hi TyMiller,
1. Have you made any recent changes on the computer?
2. When was the last time it was working fine?
3. Do you have any security software installed on the computer?
Method 1
I would suggest that you run SFC scan on the computer which would scan for corrupt system files on the computer and replace them.
The scan may take some time, so be patient. Windows will repair any corrupted or missing files that it finds. If information from the installation CD is needed to repair the problem, you may be prompted to insert your Windows XP installation disk.
Description of Windows XP and Windows Server 2003 System File Checker (Sfc.exe)
http://support.microsoft.com/kb/310747
Method 2
If the above step fails then scan and remove any malware or virus infections from the computer and check.
The below scan only works on 32 bit version of Windows
**http://onecare.live.com/site/en-us/default.htm**
You may use Microsoft security essentials to scan your computer