Keep in mind, though, that your savings may depend on how long you've had Vista installed on your PC. If you installed Vista a year ago, you may have more previous versions of system files than if you installed it a month ago, you your results may vary.

More efficient Sidebar

Microsoft also states that Sidebar gadgets now use fewer system resources. In my casual, non-scientific testing, I monitored the Sidebar's memory use on two PCs side-by-side: An HP notebook running Vista SP2 Beta and a Dell Optiplex desktop running Vista SP1, both with 2 GB of memory.

To ensure that my comparison was as fair as possible, I removed all Sidebar gadgets, restarted, then added the same set of gadgets on both PCs. Over the course of a few hours, I let the two PCs run, and performed the same tasks with the gadgets on both: Adding some, removing some, changing some settings, and poking at them every so often.

In the end, SP2 Beta did show an improvement, though again, it was slight. At first, SP2 Beta's Sidebar actually used slightly more memory than SP1's but over time, SP2 Beta showed a slight advantage. Over the course of an afternoon, SP2 Beta's Sidebar used maybe one or two fewer megabytes of memory than its SP1 counterpart.