My fairly new gaming rig had been taking a very long time to shut down, like several minutes. Since this PC was fairly new with a clean install of XP Pro SP2, I thought it unlikely I had an old application or earlier version OS messing it up. So I searched for optimization tips, and the first one I tried (after considerable research and thought) seems to have really helped: http://www.gilsmethod.com/node/56
This consists of adding an entry in the SYSTEM.INI which tells Windows to "optimize" use of the swap file by using RAM as much as it can before swapping to disk. This site, Gil's Method, has a number of interesting optimizations for Windows.
My second choice (because it involved a registry change) was something I found in an excerpt of a book, Windows XP Hacks
. This is on the O'Reilly Network site: http://www.oreillynet.com/pub/a/network/excerpt/winxphacks_chap1/
This hack involves going into the registry and disabling this key: ClearPageFileAtShutdown
Since this disables an activity which only happens at shutdown, it should speed the shutdown time. But I wasn't sure I wanted to disable this function if I didn't have to. But since the first optimization I tried seems to have done the trick, I'll leave this one alone for now.
I would like to see more recommendations on improving shutdown and startup times, so please post yours here.