OEM Windows Product Keys can be used on either 32-bit or 64-bit installs. You can request the media from Dell (if in the US, and after you have completed an 'ownership transfer') or use a disc from another system that matches the version the license is for (Home, Ultimate, etc.): support.dell.com/.../backupcd_form You can use Retail media, then activate over the phone with Microsoft (not Dell) using your Product Key: en.community.dell.com/.../3317.2-3-microsoft-windows-vista-official-iso-download-links-digital-river.aspx Just boot to the Windows DVD, delete any partitions shown to you, then hit Install ... you need to install drivers after Windows is installed, but you can address that once Windows is on. You also need to determine if you have a RAID controller that will require special drivers during the install.  The 490 could use a PERC or SAS 5 RAID card.  You can check inside the box to see where the drives are cabled to and/or check during POST to see if you have a CTRL-C or a CTRL-R prompt while devices are loading.
Just purchased a Dell Precision 490. It came preloaded with Windows 7 HP 32 bit.. The product key for Windows 7 is on the case. Along with that key there is a Windows Vista Business OEM key. My first question is how do i tell if its a key for 32 or 64 bit Windows Vista? Or can it be used for either (It doesn't specify on the key). My second question is how do i properly go about reinstalling Windows Vista. I've noticed there are alot of different people selling different reboot/reinstall/repair discs. Thanks.
Windows Vista Business OEM Product Key on Precision 490