[Answer]Sound echo

Question：I have an Acer laptop (Aspire 4539) running Vista and the sound quality has recently developed an irritating echo - music sounds as though from a large hall but voices are almost incomprehensible. I've followed the advice of JohnD in response to an earlier similar problem, but to no avail. First two steps don't change the echo sound and when booted in Safe Mode, the speakers are not active so its difficult to judge if a third party software is the cause. Any further corrective suggestions most welcome!

Answer 1：
Hi Fitzfisch,

Safe mode is diagnostic mode were some of the main services like windows update sound etc are disabled and they don't function. That is the reason why you were not able to hear any sound in safe mode.

Method 1:
To check if the issue is not with the third party software lets perform clean boot.

To perform a clean boot on a computer that is running Windows Vista, follow these steps.

1. Click Start, type msconfig in the Start Search box, and then press ENTER.

If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.

2. On the General tab, click Selective Startup.

3. Under Selective Startup, click to clear the Load Startup Items check box.

4. Click the Services tab, click to select the Hide All Microsoft Services check box, and then click Disable All.

5. Click OK.

6. When you are prompted, click Restart.

7. After the computer starts, reinstall and start the program and check whether the problem is resolved.

Check for previous issues. If your issue is resolved, follow the How to Determine what is causing the Problem section in the KB article to narrow down the exact source.

http://support.microsoft.com/kb/331796 .

To return your computer to a Normal startup mode, follow these steps.

1. Click Start in the Start Search box.

2. Type msconfig, and then press ENTER.

    If you are prompted for an administrator password or for a confirmation, type the password,          or click Continue.

3. Click the General tab.

4. Click Normal Startup - load all device drivers and services, and then click OK.

5. When you are prompted, click Restart to restart the computer

Method 2:
Uninstall the drivers from device manager and re-install them.

Click on start>Right click on computer>Manage>Device manager>Expand sound, video and game controllers>Right click on the option below and uninstall it. Now find the updated drivers from your computer manufacturer's website and install them back.

For more information and further troubleshooting you refer the link below.

Tips for fixing common sound problems.
http://windowshelp.microsoft.com/Windows/en-US/Help/1e87a3e8-c0e8-49af-980f-9eb6686f42d21033.mspx

Please let us know if you need any further assistance.

Regards,
Sreekanth
Microsoft Support