If you have Vista, 7 or 8 then to improve performance I would recommend that you run the MS utility and use that to organise the boot devices

Performance toolkit http://www.msfn.org/board/topic/146919-install-the-windows-performance-tool-kit-wpt/
Boot enhancement instructions http://www.msfn.org/board/topic/140262-how-to-speed-up-boot-process-under-windows-vista-or-windows-7/

This way you do not need to play with the registry or tweaking programmes

For the services tweaking then doing it manually is not a problem if you use BlackVipers guide http://www.blackviper.com/ just follow the destructions for your version of windows. This way you have full control