DarkPheonix, I think Dwarf nailed it -
My recommendation would be to carefully read Black Viper's guide and instead of disabling services, set them to manual. That way, they are effectively disabled (i.e. not running), but if required they will start and stop.
This is exactly the conclusion that I came to. I disabled four services that I do not need: three because I am behind a router with a firewall and one because it relates to something I am not running and probably will never run. Unlike XP and Vista, Windows 7 does a great job of turning off services that are not needed. Services set to manual do not run in the background nor use resources.
Microsoft has to engineer an OS for a huge variety of situations. It isn't that they are trying to control your computer (except for their tendency to make it idiot proof - but that's another subject), they are simply trying to make your computer work in a large variety of scenarios. Yes, there are services that you do not need. Most of these are set to manual and do not run. They do not need to be disabled. Manual setting does the trick. Do take the time to read Black Viper's comments. Windows 7 is not Vista and the services are MUCH improved over Vista.
If you do not have a home network, there are three or four others you could disable. However, all but two of these are already set to manual and do not run anyway.