Nothing to do with drivers, it is to do with the hardware being to old to work in the new motherboard. I can still use the card in another Windows 7 machine. You are looking at old technology not supported by new technology. New technology is too fast for such an old card, stuff moves on in computing. You would seem to be saying I shpuld be able to run Windows 7 on a 700 Mhz Athlon with 256Mb of ram with a 32Mb ATI video card and a 10GB hard drive???

:sarc::sarc::sarc:
Yes, it has everything to do with drivers. Motherboards which have a PCI expansion slot (which most modern motherboards do) are equipped with such to support 'legacy' devices'. The PCI standard really hasn't changed since 2002 with revision 3.0 which is backwards compatible. The last driver from Creative for my SB Live card was made in 2004 and lacks Win 7 support. That is the only issue, the lack of Win 7 support at the driver level. If you have a PCI sound blaster card and a modern motherboard with a PCI 3.0 expansion slot, an undamaged card will work just fine with the proper BIOS setting and drivers. As long as all bus/devices adheres to the standard set by the PCI Special Interest Group there should be no issues. Perhaps you are confusing PCI Express and PCI?
I'm using my SB Audigy PCI on a BIOSTAR TZ77B motherboard running an i5 3570K and 16GB of RAM by way of the KXProject drivers and have zero problems. What does that tell you? I've also tested my old SB Live! Platinum card and it works just fine even in modern games like BF3 with the proper drivers.
Your argument for new hardware being too fast for older PCI devices is rubbish. The PCI standard is the PCI standard, plain and simple. If your chipset supports PCI then it supports PCI regardless of processor speed. PCI latency may be adjusted to your liking in the BIOS.
My motherboard supports PS/2 keyboard and mouse as well and it not 'too fast' for it.