Need some help

Ok, here's the story..

About a month ago I purchased a pretty high-end customized Windows PC, but it had RAM problems since day 1. I did run the program memtest and found that the memory was bad - the store (who I paid to install the hardware), sold me bad RAM..so, I pushed for an entire refund and I succeeded (amazingly).

EXCEPT..my copy of Windows 7 Pro was OEM and was activated on this system before I returned it and got the refund.

I am hoping to use it on my newly purchased iMac 27" (My first Mac computer, btw), along with Parallels.

Now, since I returned my computer - except for Windows 7, am I able to install/activate Windows 7 on my Mac (and Parallels), without issue since my previous computer was returned? Or do I need to buy retail version? Or would Microsoft allow me to activate Windows 7 if I tell them this too?

It's probably not going to activate without a phone call. Those have always been painless for me. Not sure what the real MS stance is right now, but I'd be willing to bet if you tell them the first system was bad, you uninstalled Windows and you returned the system, they'll give you a new code.

In any case, I'd let someone at MS say no while you're trying to activate it, not anyone else.