it will either put the entry to remove it back in add remove programs or the installer will give you the option of removing it when you run it, either way you can uninstall it.
(why are you removing it, it's far better than IE)
Go to Program files in 'Local Disk' in My Computer and there will be a mozilla firefox folder, in there ther may be an uninstall option. try it it might work, it might not even be there but thats all i can think of, hope it helps.