i e not working in windows xp p

I HAVE A IBM P4 2.4GHZ SYSTEM WHERE THE INTERNET EXPLORER IS NOT WORKING .SO I USED MOZILLA BROWSER FOR DOWNLOADING THE INTERNET EXPLORER FROM MICROSOFT SITE. I AM NOT ABLE TO REMOVE THE INTERNET EXPLORER FROM THE SYSTEM.KINDLY HELP ME IN REMOVING THE I.E AND REINSTALLING THE I.E.
THANKING YOU.
S.CHANDRASHEKAR