Okay....here goes......I have no sound on a system I've built. It has a biostar mobo with an onboard Realtek '97 for VIA Audio Controller. The OS is Windows XP SP3 with everything updated. I have installed all the proper drivers, directly from either Biostar or Realtek. Whether I use simple headphones or simple stereo (amplified) computer speakers, I have no sound. The Windows hardware test (the one where you read into the microphone and it shows both the record and playback levels shows great level in each, but I have no sound, despite what Windows says. I've installed all Chipset drivers as well, directly from Biostar. I've run a dxdiag and this is the error code it is showing - "DirectSound test results: Failure at step 19 (User verification of software): HRESULT = 0x00000000 (error code) dxdiag also noted that the the ALCXWDM.SYS is not digitally signed by WHQL (the Windows Hardware Quality Lab), but I have never had that be an issue. Many drivers are not signed. Anybody have any idea? I've built dozens of systems over the years, repaired many more, and I have never dealt with this.