Help removing and reinstalling Civ4

Hi I had civ4 running on one of those pocket media drives that you can use as an external drive when I got a virus on my computer that changed the actual drive letter assignment of it I think from J to L so civ wouldnt work. I ended up just deleting the civ4 folder from the drive thinking I could simply reinstall it but the setup program will only try to uninstall civ when I run it and end up with an error that some of the files cannot be found. Does anyone know where all the civilization 4 files are stored and the reg keys so that I can try to manually remove it completely and reinstall it fresh? I'm using vista btw