Oh yes this is very possible even with a high end PC.
What you need to do is remove application from your the startup.
You can do that when you run MSconfig and go to the startup tab. Here you'll find a list of apps and programs that autostart everytime windows loads. Remove the ones you dont need, there are some system programs that have to stay in there like load powerprofile, some ending with MSG, systray and some others. Just make sure that you only take out what you know about.
http://www2.whidbey.com/djdenham/Uncheck.htm
follow this link for and indication of what you can remove