The problem began as "the microphone doesn't work". nVidia chip on an ASUS A7N8X-X motherboard Windows XP Home SP2 Athlon 1.8 GHZ 768 MB ram Direct X 9.0 2 different microphones were tried. The user installed a Creative SB 16 PCI card, but the driver installation routine hung at SBRES32.dll, which he left running for > 8 hrs. I tried a Creative SB Audigy card. The drivers installed smoothly, but I couldn't get audio out of a CD. I can get audio out, using Windows sounds [ *.wav ]. Control panel > sounds & Multi-media > all devices set to the SB Audigy. Microphone test failed our ears & Windows Hardware test. I verified that none of the sound device settings were muted. When I plugged the speaker cable into the nVidia port, the CD was heard. Then, from the speakers, came a woo woo woo garbled, then the PC froze. I unplugged the PC, removed the PCI sound cards, booted to safe mode; re-booted to normal mode. CD & *.wav out worked. No "bangs" in device manager. I tried 2 different PCI slots. Speaker setting set, correctly, to desktop speakers. In event viewer, MCSTRM service failed, event ID 7000. I look forward to your guidance.