New update for XP Mode allows for non-VT PCs
Windows 7 Professional, Enterprise, and Ultimate came with a downloadable feature called Windows XP Mode. This allowed the end user to run a "free" copy of Windows XP in a virtual computer on the same PC they were running 32 or 64 bit versions of Windows 7. This can be useful for a number reasons: browsing in a sandbox to prevent infection of the main system, overcome compatibility issues, or to run different versions of software, such as Internet Explorer.
Until recently, Microsoft required that a PC have special technology built into the hadware that allowed virtual computers to run more efficiently. This was either Intel’s "Virtualization Technology" (VT Enabled) or AMD-V.
With the new update, Virtualization Technology is no longer required.
You can find the update at the KB article website: http://support.microsoft.com/kb/977206 or the Windows XP Mode download page.
Known issues:
