You can disable the automatic startup programs very easily with "MSConfig.exe" program which is available in Windows XP and Vista machines.
1. Click Start (Orb) button and type "MSConfig". Select "Msconfig.exe" file from the start menu results.
2. Go to Start-up tab and disable the programs you don’t need.
Remember it will ask you to restart your computer right-away. You may choose to restart later (if so, click No). After you reboot, the MSConfig program will pop up and notify about the disabled programs.