Basically, what 'hyperthreading' boils down to is allowing the CPU to utilize extra hardware to run a second program thread, instead of the single main thread that most do. In its own way, it is very much like MMX; something that knows what it is can exploit it for benefit. Something that doesn't either ignores it, or some program call rouses it enough to get in the way. For the very few programs out there that are optimized for HT, it speeds them up considerably (most of those programs tend to be things like video editing suites. Some of the big 3D apps have the optimizations, as well). For older programs, it can be a liability. Disabling hyperthreading is easy; on startup of your system, hit the delete key to go into the BIOS. Look around in the more advanced areas; there should be a line that says 'Hyperthreading' and to the right should be a 'YES'. Arrow down until the cursor bar is over this line, then hit page down on the keyboard; this should change it to 'NO'. If it does, then press F10, when it asks if you want to save the changes say Yes, and let the system reboot. You just turned HT off.