In message <>, Ken Blake No, it's just intellectually unsatisfying. Windows - and software, from myriad sources, that runs under it - is extremely complex these days, and so much _does_ cause things to "silt up": OK, some _very_ conscientious (and knowledgeable) people this may not apply to, but most of us find that the registry, the hard disc, and the startup (and continuously running) parts of a Windows installation do gain lots of things we don't understand, and therefore can't easily decide whether to remove or not. It's what eventually makes most people buy a new computer, I suspect - the fact that their old one has become a lot less responsive than when it was new. Sure, a reinstall would cure it, but most people are reluctant to do that - not least because they can't _remember_ how they set up things just the way they have and like them (apart from the speed drop) now. I take your points that ...  .... and ... ; it's just _irritating_ that the unnecessary stuff is there, since we know that removing such chaff in the startup and running parts _does_ speed things up. IMO, the registry, as originally conceived (around the time of Windows 3.11?) as a central repository for lots of settings, was a Good Idea - and, while it used human-readable keys etc., remained so; however, partly because of copy-protection reasons and partly because of lazy programming, it became full of incomprehensible strings of numbers, and is now a necessary evil.