@Jari:
Well DirectX is composed of many sub libraries: DirectSound, DirectMusic, DirectInput, DirectDraw, Direct3D, DirectPlay and DirectShow (DirectDraw and Direct3D were united in 8.0 under the name DirectGraphics, DirectMusic only appeared in 6.1). What I was meaning was that the developper could have used the DirectDraw/Direct3D libraries and neglected the DirectSound part: this would mean that my graphic card would not be a cause of my problem but my sound card would be.
Also, from my latest edit, I just found out an exerpt showing SoundBlaster Live! IRQ problems which would mean that the problem would not lie in ff7 or DirectX5 but in my sound card.
As to Gabriel Knight he was sure it was the 3rd. It was a while ago under win2000 and at that moment the application compatibility toolkit was not operational. I conceed I do not have the detail of his sound card to check if it was sound card related or not.
[EDIT: @chesso
The following link may give you insight about how to remove your IRQ9 based problem.
http://www.soundonsound.com/sos/Mar02/articles/pcmusician0302.asp]
Red.
[2nd Edit:
I changed the computer driver to standard PC and got all my IRQs with no conflicts in the range 0-15 (no BIOS modification leaving the other OS in dual boot untouched). My sound card still blocks ff7. I am at a loss here -_- .
Meanwhile for those interested here is a clean procedure to switch the OS from ACPI to standard PCI (WinXP. Could work with Win2k but untested).
1- insert your OS CD and select update the OS: this process takes about 25 min.
2- once back on desktop go to the device manager, select system devices and uninstall PCI Bus. Do not reboot.
3- select resources by connexion, go to IRQ and uninstall Microsoft APCI. Do not reboot.
4- back to the device manager, select my computer and change the driver. Precise you want to select the driver from a list. You select PC standard. Reboot.
5- when back to the OS, let it reinstall all drivers and you are ready.
Thanks
Red.]