Under the startup tab in msconfig, you don't actually need any of these for the computer to run so don't be scared to switch 'em off. Just re-enable them if you find you're missing something, like your virus scanner. Rather than using the services tab I would go to start->run and type "services.msc" as this will usually give you a decription of the service and what it does. There's a fair whack of stuff you can disable, even from the standard MS services. Google for some guides. You should be able to slim things down to around 20 processes without being too extreme. You will save loads of memory, your computer will start faster and run more reliably so defo worth it.