Is there a way to tell if you are using 16-bit programs? Just because it's a 16-bit program, does that mean if you remove support, you can't install it?

well if you had one 16-bit program running you can see "wowexec.exe" process running. or something like that. unfortunately I dont know about others really, but I could think you're not able to run/install them if you remove 16-bit support but you can always try