Now that I have one of my Windows XP workstations running full time on a Microsoft Virtual PC I decided that it was time to reduce the amount of RAM that it consumes. Nearly everyone knows there services in Windows that you can turn off to save memory and generally improve performance. What most people don't know (including me) was exactly what services you can and can't disable.
That is now all solved with the Black Viper site. You can choose any current version of Windows and see which services can be disabled. You'll find a table that gives you options for each version and allows you to customize your settings based on what type of system you want to run ( i.e. minimal, power user, etc).
After using the information on the Black Viper site, I was able to reduce my Windows XP RAM usage from 415MB down to 305MB. Sure 100MB of RAM may not sound like much but that is greater than a 25% reduction! Best part was that after a reboot the system didn't complain and everything I needed ran.
So if you are looking to pare down the amount of RAM Windows is using take a look at the Black Viper site.