The solution requires some knowledge of registry.

    The problem occur when you messed up installation of a program on your Windows, especially games which cames with multiple CDs.

  ;  You placed disc 1 to your rom (or disc image to your virtual drive) and the setup starts to run, everything when well until you changed to the 2nd installation disc as installer request, it somehows stop responding - most probably due to the bloody buggy installer/ or your old cdrom you have which lead to slow boot-up/ swap disc image and click to proceed installation too fast, which cause both of your virtual drive program (e.g. - Alcohol 120%) & the installer to crash/ est. est., whichever the cause.

    And after you clear everything backed to desktop, hard reboot or not, tried to launch the setup again. Now the problem occured, it says you've installed the game/application and asked if you would like to remove it (some game/application just don't have the "repair/reinstall" option, nonetheless a not working one). You proceeded to remove it and launch the installer again while it telling you shit like - "You have not probably uninstalled...click to uninstall", "Are you sure you want to remove...completely".

Finally, solution to such case:

1. Hit Windows button & R - it will open the "RUN" dialog, and type "regedit" (without quotes) & ENTER.
2. Browse to - HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall
3. Find the software folder there and delete the whole of it, be sure to make a backup - select the folder > right click > export > save it somewhere.

    That should do the trick, run the installer again and you should be on your way, just be careful not to mess it up again :p

    Btw, you might try out maintanence program with "software uninstalling" function, CCleaner (Crap Cleaner) for example, might just work out ok.