Style XP seems to clunky to me, not to mention they still attach 3rd party junk (spyware) to some of their themes even if you pay for it. Windowsblinds has gotten much better and uses much less resources than older versions. I use neither.
I went to Belchfire.net and installed the "multi-patcher". It replaces the uxtheme.dll allowing you to install unsigned visual styles and themes within Windows without having a 3rd party app installed.
The patcher is free though they do have a pay product as well. Use the multi-patcher, it's nice. They have a full tutorial explaining it all and allot of nice themes and styles. You can use themes and styles from almost anywhere if you don't like the ones on Belchfire so long as you can extract them properly.
Here's the tutorial for installing visual styles and themes once you have the "multi-patcher" installed.
Read everything through the tutorial. The multi-patcher will work for stand-alone Themes and Visual Styles. Certain programs such as Windowsblinds package their skins in a way that is not usable by the multi-patcher. The tutorial explains it all.
