I've dealt with similar issues when trying to get older hardware running on newer Windows systems, so I completely understand the challenges you're facing with the C-Media CMI8738 chipset. Finding drivers for legacy hardware can certainly be a bit tricky, especially since manufacturers sometimes stop updating the drivers.
A good starting point for drivers is always the manufacturer's website, though in this case, C-Media's official site might not have the most up-to-date or compatible drivers for newer versions of Windows. In my experience, trusted third-party sites like DriverGuide or Softpedia often have archives of older drivers that could be helpful. I've managed to revive a few older cards by finding compatible drivers there.
For maximizing compatibility with modern Windows versions, here’s what I typically do:
Install in Compatibility Mode: Right-click the driver installer and choose "Properties," then navigate to the "Compatibility" tab. Here, select an older Windows version that the driver is known to work with.
Use Windows Update: Sometimes Windows itself can find a generic driver that might not offer all features but will at least get the card functioning.
Check Forums and Communities: Places like Reddit, Tom’s Hardware, or even niche forums dedicated to retro computing might have user-generated drivers or patched versions that can extend compatibility.
Manual Installation: If automatic installation doesn’t work, you might try manually installing the driver through the Device Manager. Sometimes the installer itself fails, but the driver files can still be used if updated through Device Manager.
When working with such old hardware, performance might not match modern standards fully, but often you can still achieve decent sound quality. Sometimes tweaking settings like hardware acceleration or changing sampling rates in the sound card settings can optimize performance.
As a caution, always ensure your drivers are scanned for malware and are from reputable sources because older drivers can sometimes become a vector for threats.
I'd be curious to know if the manufacturer provided any updates or recommendations for this chipset, so if you find any interesting information, do share. If you need further details on any of these methods, feel free to ask!