I'm on Win XP 32bit SP3.
However, Antares does have a 10 day functioning download demo to
see if it works with your system.
I had Autotune 3 on an older machine, but didn't transfer over to my present DAW.
It might have been DX if I recall......
Odd that it doesn't read your vst from the folder.....
Best of luck with the demo.
If you're intersted, the new EVO is pretty nice.... leaves the sound a bit clearer
and the new graphical mode is much improved and highly flexible when you need it.
Klos Studios