How do I add the D drive to the Cleaner?

I'm a newbie and the setup only added the "C" and "A" drives (yes it is an old computer) to the options for cleaning. How do I add the "D" drive, or "E", for that matter to CCleaner?

CCleaner can't clean anything on D:\, unless it is the target of an environment variable (e.g. sometimes, the Program Files folder is on D:\ );)

CCleaner can't clean anything on D:\, unless it is the target of an environment variable (e.g. sometimes, the Program Files folder is on D:\ );)

Thanks.