In Windows 7, running Windows XP mode requires that the computer support Virtualization Technology (VT). Most modern Intel and AMD CPUs support VT, but I am learning to my woe and dismay that some motherboards — including some relatively new ones — do not.

This includes the Asus P5K motherboard that has otherwise proven itself to be a capable and rock-solid Windows 7 test platform: I’d been running it with 12 GB of RAM installed and it was fast, agile, and let me run as many as half-a-dozen VMs with Virtual PC 2007 and XP, Vista, and various Windows 7 versions.

Upon learning this, I could suddenly understand why my test platform wouldn’t run Windows XP mode. I called my resident hardware guru, Toby, and asked him if any relief might be at hand. He said “Download the Asus BIOS Update utility, and grab the latest BIOS. It might fix this problem, if Asus has added VT support to a later release.” What he didn’t tell me, and I didn’t know, was that the P5K models are subject to total BIOS obliteration if the flash fails to complete or to validate properly. When I flashed the BIOS and saw the latter failure reported, I figured “No problem. I’ll reload the old BIOS on my next boot.” Not gonna happen, apparently: the BIOS never even started to POST so I had no way to get back into the system to make the change.

The BIOS is completely hosed, and I’ve ordered a new BIOS chip from an eBay supplier for a mere $20. My gut feel is that the chip may restore the motherboard to operational status, but it’s unlikely that I’ll get the VT support that I need from this motherboard. I’m planning to order a new, ultra-stable model from Asus or Gigabyte to replace it, probably with the P45 or a newer chipset, which is much more likely to suppport the virtualization technology I need.

In the meantime, my primary test machine is down for the count until the new BIOS chip arrives in the mail. Good thing I’ve got another backup PC to put in its place in the meantime. It’ll have to wait until this weekend, however, when I should have time to run through yet another install and finish-out for Windows 7 on my currently unused Vista Media Center box. Wish me luck!