Try the good old DriverGuide.com
www.driverguide.com
Username: Driver
Password: All
If you do not know what the sound card make or model is, try contacting Acer, or failing that, use SiSoft Sandra Professional (version 2002 or later preferably) to find out details on your soundcard. If you can't get SiSoft Sandra PM me and I'll see if I can get you a copy.
PC Spec: AMD Athlon XP 2000+, ECS K7S5A Motherboard, 768MB SDRAM PC133, Sparkle nVidia Riva TNT2 M64 32MB AGP Graphics Card, Creative Sound Blaster Audigy 2 6.1, Windows XP