You could probably look up the registry, but beware! This can royally screw up your computer! If you want to do it still, Windows+R, type 'regedit' without quotes and Enter. Search for the program's name or developer (usually under HKEY_LOCAL_MACHINE/Software, and probably Wow6432Node if you're on 64 bits), then 'File > Export' the registry key; that'll save a backup. Then you can try deleting it, and see if install succeeds. Repeat until it works, and if it doesn't, just run all the .reg files you'll have gotten from saving those keys, it'll re-apply what you deleted. And this is why you should make backups.
I make no guarantee that this will work, or not damage your computer!
If you're being extra careful, it should be fine, but use at your own risk.