I can understand issue.. Please check this image and follow it up..Method 1:
Click start lower left on your desktop.
panel then double click sounds and audio devices.
Click audio tab
ensure your speakers and mic are the default devices do the same with
the voice tab.
If not change them and click o.k.
You can also check
your equipment while you are there.
Also click actions top line of the
messenger window, scroll down and run voice setup.
This should work for you. If not then try the another method.Method 2:
Please follow the instructions as per below image.
Try this and i hope it will work.. All the very best..