Two OS on one computer

I have a license for Directory Opus 9 for one computer is it possible to install this software on two OS on the same computer. I registered the program with Windows XP but now I also have Windows 7 RC on the same computer for testing the new system. Will my license allow my two test Dir Opus on the new OS or will I have to uninstall Windows XP?

Since it's the same physical computer and you're not using both installs at once, that should be fine, at least by my understanding of the licence.

Yes, you install it on 2 OS's.

What I have is a Hard Drive Trayless Caddy for my 2 OS's, one is XP for my Train Sims and the other for Vista for normal computing.

All I have to do (rather than dual boot) is open the caddy door, slide out the drive, slide in the other drive, close the door and off I go, all of 6 seconds.

When W7 Final is released I'll be using both W7 Pro x64 and W7 Home Premium x64

I'll use Pro x64 for normal computing and x64 Home Premium for my Train Sims, to do this I pre-ordered both at the special price.

The question wasn't whether it was physical possible to use two copies but rather if it was within the terms of the license agreement.