For a couple of weeks Skype has not been working on my computer. Yesterday and today I finally got around to looking into what was causing the problem.
The crash report for Skype was saying that the problem file was "nvdxgiwrap.dll." When I googled that .dll file it came up in error messages for crashes of other programs as well. In one forum the suggestion was to update the nvidia video drivers.
I went to the nvidia.com web site and first selected the update option that would detect the video card on my laptop, but each time I downloaded the suggested drivers the install process never completed. So next I searched for the specific driver on my laptop (the sticker was still near the keyboard so finding the right type was easy) and downloaded it. This time the install process completed and after rebooting my computer Skype is once again working.
This is the very first problem I have ever had in years of using Skype and it comes within weeks of Microsoft merging their Live Messenger program into it Skype. I hope this was only a co-incidence of timing.