TuneXP

Although it might be a bit too technical for average folks, this tiny, free utility nonetheless offers a helpful set of optimization tools for more advanced users of Windows XP. TuneXP's interface is certainly no beauty, but since all of its tools are accessible via menu items, it's simple enough to operate. The Memory and File System section lets you perform tweaks such as accelerating DLL unloading and defraging boot files. The other system tools are organized into categories such as Internet, Hardware, and Services. While many of the program's features will go over the heads of those who aren't technically inclined, we're glad the help files fully explain what each part of the program does. Best of all, TuneXP is totally free, making it a fine pick for those who suspect their OS could be in better shape than it currently is.