These are mostly customized installs with a few services disabled, right? An easier task would be to simply do a Control Panel -> Administrative Tools -> Services, and read the 'Description' for all the Services that are running. You can disable the ones you don't need and check for any problems that crop up.
Why trust someone else's idea of 'what's important' and 'what's not'? Maybe that dude doesn't have a wireless router and he disabled all wireless-related services. Next thing you know, you are baffled why your '1337 gaming XP build' won't work with your network.
Potential headaches just to save maybe a few megs of RAM and <5% CPU cycles.