If you have your windows install disc you may be able to put that back in the drive, and go to the add/remove programs control panel applet. From there it might be under "windows components", select to re-install it. That might do it. There are other ways to if that does not work.
Also keep it on there even if you use another browser. Its just not good to remove it because its like the core browser. Just choose not to use it as your default browser.