What could slow down an already horrid OS?
"My PC took far too much time in finding files for programs to use, in finding directory items, thumbnails etc. Very annoying. After rebuilding the index, which takes time, the machine was as fast as ever. Lovely."
You are missing the whole point. The OS shouldn't take eons to locate files in the first place. The system is obviously so bloated it has to use another service to "find" itself. Wonderful.
-Tim