For the benefit of anyone else arriving here looking for the answer, here's a more generic means of locating it, especially if MySQL has been installed somewhere other than the default location (something I'm prone to do).
Searching each of the local drives for "mysql", which will locate both the program and data folders, as "mysql" forms part of the executable name, regardless of version, and there will always be a "mysql" table.
The log files may be in a different location altogether and the best way to locate those is through the config file, which on Windows will normally be named "my.ini". However, if someone has created this installation from source that file could potentially be called anything at all but that would definitely be an unusual case.
Ideally you should uninstall the conventional way (add/remove programs or whatever Microsoft has named it this week) first but if for some reason you're just going to delete everything don't forget to stop the MySQl service(s) first.