Possible Duplicate:
When reinstalling Windows 7, does the language, version, architecture (64-bit or 32-bit) or source (OEM, retail, or MSDN) matter?
I just bought A Dell Opiplex 960 w/ Win 7 (32 bit) and I want to also have the 64 bit for testing (installed on a separate partition).
I went to the Win7.Dell.com site but it's not validating my Service Code (even though I bought it 20 days ago).
Can I got directly to Microsoft for it? And how?
you should contact Dell regarding the Service Code (which you may need for warranty issues).
as for Windows 7 x64, if you bought the computer with Windows 7 x86 you will have to purchase the retail version of Windows 7 x64 as you're not entitled for both versions from one OEM license.
If you just want to test it, Microsoft offers a free trial of Windows 7 Enterprise (x86 & x64), you can use it for 90 days
Your serial key is valid for either and you should of got a choice when purchasing.
I am not sure if your licence covers you for using them both at the same time even if on the same machine. I think the answer would be no as I asked Microsoft directly a similar question a few years ago.
Your best bet is to ask Dell directly, you bought the machine from them and they should be the ones responsible for this sort of thing.
You would only have the option to install 32 & 64 bit if you purchased windows 7 as a retail product.
Any operating system bundled with a system will, under most situations always be an OEM product. Which apart from costing you 150$ less then it's retail alternative, is locked to the system it is pre-installed on via the eula agreement you had to agree to when starting your new system.
If you just want to test the 64bit on a different partition I would agree with Molly and install the Trial Enterprise edition of the software. When the trial runs out you can rearm the expiry date 3 times to squeeze another 90 days out of the install. Instructions can be found here
