Acer Aspire 4250 Service Manual page 140

Speakers are selected as the default audio device (green check mark).
NOTE:
NOTE:
If Speakers does not show, right-click on the Playback tab and select Show
Disabled Devices (clear by default).
7. Select Speakers and click Configure to start Speaker Setup. Follow the on-screen
prompts to configure the speakers.
8. Remove any recently installed hardware or software.
9. Restore system and file settings from a known good date using System Restore.
10. If the issue is remains, repeat step 9, selecting an earlier time and date.
11. Reinstall the operating system.
12. If the issue is still not resolved, refer to
4-12
Online Support Information.
Troubleshooting