Click on Start/run and put in Msconfig in the Open window and hit OK.
This web page is just a lead
into Start-Up Problems  Everything
You need to know about msconfig is
on this page.  This page just takes
you to the System Utility for the changes
Before making any changes go all
over Start-Up Problems

The programs listed in the "System Configuration Utility"
Are starting up when you start the computer.  These programs are running and pulls your computer resoures  down.
We want to have just the programs
we need running when we start the Computer.  Remember you are not deleting a program. 
          Rule of thumb do not shut down a program that starts with Windows i C:/WINDOWS/ 
Example C:\WINDOWS\scanregw.exe/autorun  Also if you are not sure go to  Start-Up Problems 
This will answer most Questions.  Go to this site and print it out in color.  Will make it real clear  with graphics.
Start-Up Problems will answer all your questions

C:\Program Files\real\Update  Any program in Program Files is usually a program that can be uncheck. 
Remember your anti viruses will be in Program Files.  You want these Programs to start up.

When unchecking any program you have to do a restart for it to take effect. 
When it restarts XP users will get a dialog box tell them a change has been
made in the register.  Just ck the box in the lower left hand corner so it
doesn't come up ever time you start the computer.  In closing all your
questions will be answered in Start-up Problems