trying to figure out what "services" in task manager arenot necessary to run
~~they will be re-enabled if you restart~~
apple mobile device support
(if you have itunes)
Adobe acrobat update service
PS: if you are doing this for gaming, Vista Services Optimizer : http://download.cnet.com/Vista-Services-Optimizer/3000-... : has a game mode where you can disable all the programs you dont need, and than re-enable them when you are done gaming. they also have an automatic and manual windows optimization....
Research what is running, what programs you have installed that use what is running, what programs Windows is running based on your installed options, then the remaining may not be needed. Basically go down the list of processes one by one, and see what is using it.