Windows 7 professional 64 bit to 32 bit

I'm a real novice. Recently purchased HP desktop with Win 7 professional 64 bit OS preloaded but was told the proprietary scanner will only use 32 bit OS. I downloaded the 32 bit Window 7 prof x86 ISO. How do i reformat and repartion the hard drive? Do I need D: drive? How do I install the ISO, Should it be bootable?
I have the Window 7 pro OA product key on the case.

thanks jtf

Welcome jtfdc. If your running 7 pro then I believe you will have or can download for free the Windows Virtual PC and run in XP mode. Sort of like an O/S within the O/S. It will allow you to load and run programs (and I assume hardware) as if it were a 'real' XP machine.
What I don't know is if it will give you a virtual 64bit or 32bit. Environment. Others will pitch in later with more info for you.

jtfdc1948, welcome to the forum! One of the advantages of 7 Pro, perhaps the main one, is having Windows Virtual PC w/XP Mode installed. It was created for users like you who needs their legacy software (and hardware, such as, but not limited to, printers) to work.

It's a virtual XP Pro SP3 system, and you can run anything on it that you ran on a XP based computer. Except gaming, it's not the optimal environment for it. The more RAM that you are able to "lend" to it, the better it will perform. For me, 1280MB (1.25GB) works well for me, though if I had a high power CPU with 6GB or more RAM, I'd lend it 3GB. Never lend over half of your installed RAM, as your main OS will be anemic.

And read the site carefully, you'll need to enable HAV in the BIOS, for best performance. It's a simple thing to do. If you have further questions, please post.

Too, if you have issues once you have XP Mode installed, please post it in the Virtualization section of the forum, those of us who has some experience will see it, and can offer assistance.

Windows Virtual PC w/XP Mode can be found at:

http://www.microsoft.com/windows/virtual-pc/

Best of Luck,
Cat