It's a bit of confusing wierdness caused by the patches. You can manually uninstall the game by doing the steps below.
Delete the Civilization III folder.
Use regedit to delete the following keys:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu\&Programs\Infogrames Interactive\Civilization III]
[HKEY_LOCAL_MACHINE\Software\Infogrames Interactive\Civilization III]
[HKEY_USERS\.DEFAULT\Software\Microsoft\Windows\CurrentVersion\Explorer\MenuOrder\Start Menu\&Programs\Infogrames Interactive\Civilization III]
The fourth one is a bit more complicated and the most important. In the registry editor, if you follow the folders to HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall, you will need to look for a folder with a name similar to {978A2104-8363-11D4-AA23-0000E889C4DA}. It probably won't be this exact one, but if you click on the entries, there should be one that has a DisplayName that is "Civilization III". Once you determine which key it is, you can delete it.
When that's all done, shut down the PC, boot up the PC, install the game, reboot the PC, then install the latest patch.
If you haven't used regedit before send me a PM or email and I'll walk you through it.
