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I'm trying to understand the installation process for windows 7.

Mainly, what things affect which version I install (32/64 bit)?

Is each disk specific to a version (i.e. Pro x86 and Pro x64 require different installation disks)?
Does product key affect version or 32/64 bit installations?

Here's the situation that prompted the questions if anyone could help with this also...

I got a MSDNAA version of Windows 7 Pro (x86) and a product key to use for it from my school. I want it to install a 64-bit version instead and I expected there to be an option during setup that would let me choose but that asumption was false and all of a sudden all of my 64-bit machine was running 32-bit windows and I was very unhappy.

I've been considering ways to remedy this, and I want to know if there's anything I can do differently during setup to install 64 bit instead (using the same product key preferably). My other option is I can get a $30 product key for a 64-bit Pro Upgrade license, and I'm wondering if I can install that over my 32-bit Pro OS, since usually the upgrade requires vista or XP.

Bottom line..How can I get my machine back to 64-bit for under $199

Thanks to the useful info that the product key is not tied to the x64/x86 architechure, I have come up with a plan that is working so far. Since I have an original disk for each architechture, I'm just doing a clean install on each computer and using the same product key on each machine. In case you're wondering why I didn't just do this in the first place, I couldn't use my laptop key on my gaming machine because it was an upgrade key and the gaming machine had no previous OS. Thanks for your help.

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up vote 4 down vote accepted

What you have is a licence key to use Windows 7 pro - not to use Windows 7 pro x86.

The serial keys are unique to the edition (Pro, Ultimate etc.) of Windows but not the platform (x86, x64).

Out of the box by using the disk alone, you can only install the edition that the disk is designed for, but it contains every edition, but only a single platform (Off topic - if you want to install a different edition, look at the Windows Automated Installation Kit / WAIK, as generating your own auto install file will overwrite the one on the disk.)

If you go to wherever you got the Windows 7 disk from, you should be able to get the alternate media that will cover you for x64.

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All good info. Also note that you won't be able to do an in-place upgrade from 32 bit to 64 bit (of any editions or versions of Windows). Either back up settings to restore, or use USMT. Since you have not had it installed long maybe not too hard to simply start over. – AdamV Nov 17 '09 at 22:23
Alright, thanks for the info. – CSharperWithJava Nov 19 '09 at 15:56

Each of the two DVDs (64-bit / 32-bit) is for different hardware. I am surprised that the hardware did not reject the 'Wrong DVD'. My information is that you may use each product key for only one installation.

As for the product key, with an upgrade I found that installation completed without asking for the 24 digits. What I did was go to the Control Panel, System and 'Change product key' is down at the bottom. This is also where it display the System Type: 64-bit or 32-bit.

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OP has 64-bit hardware, which won't reject a 32-bit installer disk. – Joe Internet Nov 18 '09 at 0:50
Exactly. Most computers these days are 64 bit – Josh Hunt Nov 18 '09 at 2:47

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