Delete or rename your wine profile directory. The default wine profile directory is located in your home: `~/.wine`. Delete or rename that directory and wine will create a new profile directory. The effect is similar to reinstalling windows. Note that all your settings and other customization in wine will be gone too.
You can set up a per application wine profile like this:
WINEPREFIX=~/wine/someapp/profile wine ~/wine/someapp/someapp.exe