Now, right click on the file that was created and select Show in Windows Explorer.
From Windows Explorer, change the file extension on the .m4a file to .m4r to have iTunes recognize this as an iPhone ringtone. If you are unable to see the file extension, refer to the Essential Windows 7 Tweaks: Part 1 article.
With iTunes open and your iPhone connected, drag your new ringtone file to your Library to associate it as a ringtone.
When the processing is done, SYNC your iPhone and enjoy your new sounds.