How do I know this was the reason? The speakers went crazy when the application failed. There is a constant hum in the internal speakers(increases when volume control is tuned up). What is wrong? Perhaps not the speakers to blame as once in a while the speakers are quite. Sometimes the sound starts as soon as window starts (Windows 7 Ultimate) on a Acer 4810TZ-4011 notebook. The drivers are from Microsoft. I suspect that the drivers are kaput (corrupted). Where do I get these files as they all belong to the driver of the device: High Definition Audio Drive C:\Windows\Sytem32\drivers\dmk.sys C:\Windows\Sytem32\drivers\HdAudio.sys C:\Windows\Sytem32\drivers\portcls.sys C:\Windows\Sytem32\drivers\SysFxUI.dll C:\Windows\Sytem32\drivers\WMALFXGFXDSP.dll File version: 6.1.7600.16385(win7_rtm.090713-1255) I need this urgently and so I appeciate if someone can help. mysorian

Hi Jayaram, Please check if the issue can be resolved by System Restore. If the issue persists, reinstall the sound card driver by the steps below: 1. Click the Start Button, type Device Manager in the Search bar and press "Enter". Click Continue if necessary. 2. Double click to expand the "Sound, video and game controllers". 3. Right click the sound card and click Uninstall. 4. Restart the computer. 5. Run Windows Update to download the sound card driver. If the sound card driver cannot be downloaded, you can go to the manufacturer's website directly to install the driver for Windows 7. If the issue still exists, access Clean Boot to check the issue. If the issue disappears in the Clean Boot environment, you can continue to narrow down which entry is causing the issue. Hope this helps. Regards, Linda

Thanks. I think that did it. Another problem I noticed after Win 7 was that the cursor jumps back while typing forcing me to undo and go back. This has become very irksome.mysorian

Glad to hear the issue has been resolved. For the cursor jumping issue, please post a new thread for further discussion. :-)