Donny,
vArranger runs only on Windows. I run Windows 7 on my MacBook Pro and it works just great with no problems at all.

Abacus,
According to Microsoft, if you install as a full upgrade from Windows 7 there is no going back without doing a complete reformat and reinstall. Darn - wish I had known that ahead of time. There are two other install options - 1. Install on a 2nd partition 2. Install from a DVD which can be created when downloading the trial version of Windows 8.

I don't use my PC for much of anything so I'll probably just leave it as is for now. I run vArranger for gigs on my MacBook Pro so I have not lost anything.

Deane