While Microsoft's attempts to promote backwards compatibility to its users are in the right mindset they may not be in the proper system speculation set, for now anyway. According to a recent report Windows 7's "XP" mode may not work on certain popular Intel based computers.

Some computers are those such as Asus products, Dell Studio, HP Pavillion, Sony Vaio and a number of others. Including the "XP Mode" support for Windows 7 is an excellent step in the right direction for Microsoft, allowing users who do not wish to have to upgrade their software or get rewrites possibly costing thousands of dollars in upgrade costs, however, it seems that "XP Mode" will only be supported if the processor in question on a specific computer supports virtualization. The list of chips that do not support this is actually a fairly long list, but here it goes.

The Intel CPUs that do not support the features necessary for running "XP Mode" in Windows 7 are as follows, Intel Celeron, Pentium Dual-Core, Pentium M, and Atom 270 and 280 processors, also, if you have an Intel Pentium D, Core, or Core 2 Duo processor the model number should be checked against these, as these also do not work with Intel Virtualization P7350/7450, T1350, T2050/2250, T2300E/2350/2450, T5200/5250/5270/5300/5450/5470/5550/5670/5750/5800/5850/5870/5900 and T6400/6570.

To be absolutely certain that your computer's CPU does support the virtualization features, check for "Virtualization" or the abbreviation "VT" on the CPU's specifications.

Intel won't be the only chip manufacturer that has issues with this as AMD Sempron and some Athlon 64 chips also do not support virtualization, though no exact model numbers that are affected have been listed yet.