Prior to Windows Vista, a computer left alone for some time could be slow or unresponsive when one would try to use them again. This is because background processes such as search indexing and virus scanning would consume memory and take away memory from applications that were not being used. Here, application memory could eventually be moved to the page file where it is not as quickly accessible as we want. When the background processes competed, they could free the memory they had been using, but any application memory moved to the page file would remain there until called upon again. To remedy this situation, Vista introduces SuperFetch which is a memory management technology that automatically restores application memory from the paging file to physical ram when the background processes complete their work.

While this is very cool from a technical standpoint, the way SuperFetch helps you most is by improving access speeds to frequently used applications. By tracking application usage, SuperFetch is able to preload the most frequently used applications into memory. I've noticed a pretty surprising performance improvement on my lightweight notebook designed more for portability than speed. People were surprised I would load something as demanding as Vista on it (it does not even support Aero due to its weak graphics), but I'm pleased to report that it is noticeably faster running Vista than it was running Windows XP. Now for the most part, I only run Word and IE on it, and this is why it is so much faster-- with SuperFetch intelligently caching these applications for fast access it will continue to run nice and quick until I fire off a new application or something I use infrequently.