Full user review
Let me think...
Can I get back to you on that?
It's a waste of money. This utility DOES improve the performance of some systems, but let's look at why. Well, those systems aren't taking advantage of all the memory they have available, and SystemBoosterXP is caching files in memory for them.
The problem is that Windows can do the same thing, if you have the memory for it. And if you don't have enough memory for it in your system, then NOTHING can help you.
But what you can do, rather than spending $20 on a third-party utility, is enable the LargeSystemCache registry setting (a Google search will reveal more info on that--and you don't need to edit the registry manually, nor use any third-party utility. Simply go into System Properties/Advanced/Performance/Advanced, and set "Adjust for best performance of System cache".)
If you do that, and disable or at least shrink and fix the size of your paging file, you will get more performance than you would have out of SystemBoosterXP. But again, you need enough memory to do that--for Windows XP, that means at least 1.0 GB, and preferably more.