Just as aside, not all apps actaully provide an install log, or at the least in the location you would expect it to be (wonderful I know). In this case the best course of action is three-phase (and this is only after exhausting all uninstall attempts, including looking for add-on uninstallers or "cleaners" for the application at hand):
Delete app folder
DL CCleean (also known as Crap Cleaner) and perform the following actions:
Delete the install entry for the app at hand
Run a registry clean to remove any orphaned entries
As I said, this is only a last-ditch method, if all other methods have been exhausted.