As long as you know which ones you would like to stop, it is fairly simple.
Click Start> Run > type msconfig into the box > start-up tab.
This is a list of the things that start with Windows. Uncheck the ones you wish to stop. When you restart, they will not. They are not uninstalled, they will still run from the programs menu, just not during start-up.
Click Start> Run > type msconfig into the box > start-up tab.
This is a list of the things that start with Windows. Uncheck the ones you wish to stop. When you restart, they will not. They are not uninstalled, they will still run from the programs menu, just not during start-up.