I'm sure everyone has had the "pleasure" of uninstalling some software from Windows, only to have remnants of the dearly departed infere with reinstallation.  This is really unacceptable.  Software that is tested by installing only on pristine Windows installation will behave badly on the less pristine.  And the error messages are abominable.  There is no advice whatsoever when you have removed, say mySQL, only to discover that such removal didn't take any databases or passwords with it.  Just complaints that the database that you are trying to create already exists somehow.  Or that the login that you attempt is producing an access violation.   Hours are regularly burned up trying to sort out such misbehavior.