I use Windows 7 now, but when I used to use Windows XP, I could find the Windows Sound Scheme files someplace in the
C:\Application Data\, in that whole maze of folders there, but not in the main directory after your UserName where most of your application data was kept. It was someplace in the Windows Themes there, the files themselves could be found, moved, and backed-up, or put on a new Windows XP computer, without going anyplace into your registry.
I am 100% sure on this, because I used to back those sound schemes up all of the time on to CDs. Not the
.wav files in the
Windows\Media directory itself, but just the Sound Schemes that remembered which sound you assigned to which event. I lost my Windows XP hard drive, and have the computer in storage pending a solution to recover files and photos I want from that hard drive, but I don't have a working version of Windows XP, so I can't tell you exactly where to find the physical location of those Sound Schemes in your Application Data directory at this time. But you can find them without entering your Registry, I am certain of that, they had their own extension and everything.