Reboot your acer laptop and check your bios, be sure to tap the F2 key while at the bios screen otherwise it'll be quick to post and move on to windows.
In the bios check for a webcam or speaker, don't know what its named but you should be able to find it.
Save the settings and reboot into windows, if it works out, go into your sound settings through control panel.
Disable the mic and close the window, if you need the mic again, use stereo 2.0, disable echo and keep the volume at 15% - 30%.
Also tell windows not to lower all sounds or mute it, otherwise it'll raise it and screech so hard leaving you deaf for the next day or so.