You can't uninstall those .Net runtimes.
Yes, you're right, I was not thinking properly
The registry keys are "Sound_GUID" at Position
"HKEY_CURRENT_USER\SOFTWARE\Classes\VirtualStore\MACHINE\SOFTWARE\Square Soft, Inc.\Final Fantasy VII\1.00\Sound"
"HKEY_LOCAL_MACHINE\SOFTWARE\Square Soft, Inc.\Final Fantasy VII\1.00\Sound"
or for 64 Bit Systems
"HKEY_CURRENT_USER\SOFTWARE\Classes\VirtualStore\MACHINE\SOFTWARE\Wow6432Node\Square Soft, Inc.\Final Fantasy VII\1.00\Sound"
"HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Square Soft, Inc.\Final Fantasy VII\1.00\Sound"
If you set the value of each to nothing, ff7 is forced to recalculate the value.