Bob, Audition V1.5 (also V3) are both 32 bit apps. But they run fine on a 64 bit Win 10 machine, that’s what I’m running here.

I’ve been running V1.5 since 2004, bought it when it first came out, they had a special upgrade price offer at the time for people previously running Cool Edit. I couldn’t tell you how many times I’ve upgraded my computers since 2004, and Windows versions too obviously, but each time I get a new machine I reinstall Audition 1.5 and 3.0 on it, never had a problem.