I have learned that you need a new CPU both intel/AMD, your system is to outdated even with the fastest CPU possible for your board. The process to run require specific settings and specific versions of windows 7. BTW does not support games in XP Mode, more info = http://lifehacker.com/5245396/set-up-and-use-xp-mode-in..., hope that helped.
When Win 7 SP1 comes out, it won't matter. They are working software support into the system, but it won't be until the end of the year. Until then your best bet is dual booting or getting a new system.
You've also have to check motherboard capability. I'm sure all currently sold Intel/AMD cpu's support VT with the possible exception of older E5xxx (but not the new ones, you just have to ask) and E7400 (or lower) and Q8xxx.