windows has a lot more overhead than Linux (although I've done a few machines using the KDE desktop using all the file indexing features etc... and all the eye candy, and had that run as slow as windows). I don't think there's a modern version of TweakUI but there probably are windows settings that will improve performance. windows XP used to have a file indexing service running, and turning that service off sped up the machine a lot, with the downside that file searches take longer. virus scanners also slow things down because they examine every file you open or run, and there may be some settings in the antivirus software you can tweak.