For goodness sake no one is calling anyone anything just trying to make some sense of all this.

Despite all that has been said here I am running an old windows 95/98 copy of Yamaha XG Works 3 (daw) that was updated to XP when I was running windows XP.

When I bought my W7 64 for BIAB Yamaha xg works would not install under any compatibility mode (not surprising ) as even the installer would not run.
However it soon got around the Yamaha Forums that if you had an installed copy on an old Microsoft XP build you could move the whole Yamaha folder to as under.
Note I made myself way back then:

These programs will not install in W7 even under compatibility modes.
Use this pre installed copy just copy the whole folder
To program files (x86) in W7.
Also copy font file to windows fonts.
Mike Head 16-7-12.

And don’t forget the music font from the old machine,

Since that time left undisturbed in its own folder it has run in both W7 64 and is currently running in W10 64 tonight.

I am beginning to wonder if this may be the answer but you would need a working installed copy of BIAB version 10 complete in its folder from the windows OS that supported it.
Maybe this in fact this is what you may have got from Ebay originally with instruction to copy to rather than install.

Mike

BIAB2021 UltraPlus,AsusN55S1Tbssd, W10/64,Akai EIEpro
Yamaha CVP405,SquireStrat, CoolsoftVMidSynth
Novatation Impulse61 Ctr kbd, Cwalk blab Kontakt

http://mikesmusic.byethost16.com/