Sorry, should have included instructions for using msconfig to disable them.
Keep a record of what you disable so you will know what to enable if necessary at a later time.
Click on Start then Run, type msconfig and press Enter.
Click on the Startup tab and disable the ones you want.
Click Apply then OK
Reboot and see how things are.
There are excellent alternatives for RealPlayer (Real Alternative) and Quicktime (QuickTime Alternative) that are less intrusive and use less resources. You may want to think about uninstalling them and installing the alternatives.