Windows 7 activation, Retail, OEM licences

My current Windows 7 Pro 64-bit installation is running as a trial and I'll need to activate it soon.

It was installed from a retail ISO downloaded from Microsoft's old Digital River site, (an officially licensed distributor of Microsoft software). It was intended as a trial install so I could first verify that certain software and drivers worked okay. They did (eventually!) so now I want to purchase it.

I am planning on buying an OEM version of Win 7 Pro 64-bit and using that key .......... will that work?

Some Googling indicates that it might ......... or maybe not.

In short, there seem to be three main trains of thought on the matter:

a) It will work with no fuss, just type in the OEM key and it will activate via the Internet
b) I'll need to do a telephone activation and hope that the rep approves it for you
c) It won't work at all, I'll need to buy a retail key

So which is it? :)

hi, you should not have a problem with activation just so you know you wont be able to transfer it if you deside to put it on another system. it will be tied to the first machine you install it on.

Understood regarding the hardware restriction etc, thanks.

So the activation of the retail version with an OEM key will be fully automatic, no phone call required, etc?

I'm not sure, but it seems to me that maybe you'll need to call in to MS. Automatic system ask you to enter (by phone) request code and give you answer code, that you must put into appropriate field.

Sorry for my English

no you cant use an oem key with a retail copy of windows. you might be getting confused their is retail and their is oem.
OEM System Builder Licensing

Microsoft Windows 7 Professional With Service Pack 1 - 64-bit, License & Media, OEM - FQC-08289 at TigerDirect.com

I see, thanks.

Are you sure that Microsoft won't be able to help if I explain the situation, in other words I don't want to have to re-install the OEM version of Windows 7 Pro 64-bit over the retail version, so losing all of my setup, etc.

you can call them and explain your situation they might help you.

I just tried that but they weren't of much help.