ever which way
It is helpful to know specifically what someone uses to "uninstall" a program.
Sometimes the uninstall utility that comes with the game is identical with the Windows\Control Panel\Add-Remove Programs utility and sometimes it is not. One really should, in case of doubt, use both.
A great many of the problems such as those described have to do with "stuff" left in the Registry File by uninstall utilities which do not clean the Registry. If you are not good with the "innards" of your computer, you need to get professional help specific to your machine rather than just one game. It may be that a commercial utility such as
Norton's Clean Sweep
might be all you need.
In the case of the huge file, simply uninstalling the game may still leave a huge residue of "saved game" files. I don't know. I do know that Tropico
had no in-game utility for deleting old, unwanted "saved games."