Installing Win 7 Pro x64 from digitalriver with Win 7 Pro OA x86 Key?

I have a HP Pro 3300 Series MT i3-2100 PC. It came pre-installed with Windows 7 Pro 32-bit. On the product key sticker it states 'Windows 7 Pro OA'. I have checked the 'Performance Information and Tools' section in Windows and it states that my PC is 64-bit capable.

My PC was bundled with 4 HP Recovery Manager discs, but these all state 'This disc contains 32-bit software'. I want to upgrade my RAM to 8GB so would like to install a 64-bit version of Windows 7.

I would like to know if it is possible for me to do a clean install of Windows 7 Pro 64-bit downloaded from the Digital River website and activate it with my 'Windows 7 Pro OA' product key. I am aware that a product key can be used for both 32-bit and 64-bit installations as long as they are the same version of Windows 7, but can a OEM product key of Windows 7 Pro activate a copy of Windows 7 Pro downloaded from the Digital River site? (which I guess would be the retail version.)

Also, my computer is partitioned into 3 drives. C:\ - containing the Windows operating system etc. D:\ - An empty drive of about 200gb, and O:\ - HP Recovery Drive.
If I am doing a clean install of Windows 7, is it possible to retain the partitions and only wipe the C:\ drive during re-installation, allowing me to move any data I wish to keep to the D:\ drive in advance, or will it all be destroyed and I'll need to move all data to be retained onto external media beforehand?

Thanks

TimorDan

Welcome to Windows Seven Forums.

Please check this tutorial for good advice.

Clean Install : Factory COA Activation Key

A custom install will allow you to just wipe the partition that Windows will be installed on whilst leaving other partitions intact.

http://windows.microsoft.com/en-us/w...ling-Windows-7

As ever, backup up any important data first though.

I would not back up important data to another partition during reinstall as it is not a fully reliable back up method. Back it up externally to HD, stick, DVD's, another computer on the network or to Skydrive which offers 15gb free storage with each Windows Live ID.

Under the EULA you can use either 32-bit or 64-bit Win7 with each license no matter what HP tells you, as long as you can find the drivers for any devices which are not provided by the installer and then quickly updated by optional Windows Updates.

Offline Activation means that it is currently using factory OEM-SLP activation method. When you use the Product key on COA sticker that changes to OEM-COA method which is managed in MS Servers. It often requires a quick robo-call to MS to record the hardware config in their servers for your key.

Follow these steps to get a perfect factory OEM clean reinstall, based on thousands we've helped with here: Reinstalling Windows 7