Not sure what windows version you have.. but Go to your control panel. Then sounds and audio devices, you may have tabs up on top of this window.. go to sounds. Under the headings WINDOWS in that box.. scroll until you see windows log-on or start up, highly that sound, down below you will see browse, you can choose what you want the sound to be. There is also a little arrow pointing toward the right and you can hear a sample of the song.
Hope this helps, If you need anything else please feel free to ask. If you found this helpful don’t forget to click the *
what is the exact error it gives you?