Hi Matt,
According to the post above from the microsoft.com forum, it was present on the Windows 10 drive

http://answers.microsoft.com/en-us/insider/forum/insider_apps-insider_other/directmusic-in-windows-10/2a55ae1c-f234-4b87-a0ff-6524349909c3

“I did some more tinkering today, and I finally figured out what was wrong. Keeping in mind that I've been trying the 64-bit version, I happened to notice that unlike in Windows 7 & 8 64-bit, the file GM.DLS was missing from the "\Windows\SysWOW64\drivers" folder -- so I copied it over to there from the "\Windows\System32\drivers\" folder.”

Are you sure that it wasn't also present in Windows 10 in the \Windows\System32\drivers\" folder.


Have Fun!
Peter Gannon
PG Music Inc.