Note: *this is a long post but it should suffice to read only the paragraph below to solve the problem, the rest is provided in case that doesn't work.*
So I decided to register for these forums because I finally have a solution to offer, after all these times of coming here to get info. : ) Having the same type of laptop as others mentioned and the same problem, this worked after fiddling around:
Start by opening the "sound" settings box. Get there by right clicking on the speaker icon in your tray menu then clicking on 'playback devices'. OR you can type "sound" in the start menu search box.
In the playback tab right click on 'speakers and headphones' then click on 'properties'.
In the advanced tab uncheck 'allow applications to take exclusive control of this device'
Click apply.
This worked for me and nothing else was needed but if this doesn't work for you you could try unchecking the related box below and the same for the 'communications and headphones' device.
In addition to those settings you could also play around by changing which is the default device for playback and which is default device for communication.
Also of interest is the last tab on that box where it talks about windows automatically adjusting the volume levels when you are using your computer to receive telephone calls. I set mine to "When windows detects communication activity: Do Nothing"
In skype you can go to Tools/Options/Audio Settings and in the "speakers" drop down box change the selection. It works for me on "speakers and headphones" instead of "communication headphones" which is strange because we want it to go to your headset, but anyway that's something else to try playing around with if it still doesn't work.
If none of these things work alone by themselves of course the idea would be to try different combinations of settings.
If nothing else works, as a bandaid solution you can disable the laptop's internal speakers, which will force the sound to go through the headset. Which can be done as follows:
right click speaker icon on tray menu.
click "playback devices"
right click on "speakers and headphones"
click 'disable'
You can right click in the white space on the sound control box and then check "show disabled devices" to easily re enable it.
If any of this works for anyone feel free to let us know. It would also be great to know my first try at giving tech advice was a success