Internet explorer is required to download windows updates (try going to their site in firefox, etc...). Microsoft is trying to build their future OSs around explorer and IE. It is very very recommended to not uninstall IE. There is no great way to completely remove it. If you go to your control panel, then to add/remove programs and then in left bar click add/remove windows components, in the new box, you can uncheck internet explorer and click OK, but all that really does is removes the shortcuts to the program. Uninstalling IE for real (deleting the files) again, will prohibit you from installing windows updates, but do, let me know if you're still interested.
Kevin