Another proof for the poor Add/remove application for windows. The problem is that there are some keys in the registry, suggesting the game is still there, although practically, it isn't. Here's what you should try, get an application called Ccleaner from here(Free). It has an uninstall tool listed under tools. If the game is listed under, try uninstalling. In case it isn't, or anyways, for the sake of your computer run a registry scan (On Ccleaner as well). At the end, backup your registry (Ccleaner will tell you what to do) and fix the errors. Now, try to reinstall.