My computer will only boot-up in the safe mode.I am running XP

Any changes that either happened or that you perhaps made to your computer around the time that the problem started; particularly any Software or Hardware that you installed or setup.

What OS?

Check this
-click start, run and type msconfig
Hit enter
-Go to Boot.ini tab
-Make sure there is no check mark in the /SAFEBOOT box, if there is, take check mark out and click Apply and let reboot