rst of all delete application data files of Skype from your system.
To do so, go to C drive and open “users” folder. Locate App Data folder in it.
If you are not able to locate it, it might be hidden in the system. To unhide it, select the tab view on the top left corner. A drop down will appear.
In this window, check the box with “Show hidden, files, folders and drives” option.
Click on “Apply” and you will be able to see AppData folder. Double click on it.
Delete all the files present under this folder.
Now you will need to re-install the Skype.
Restart your PC after the application gets uninstalled.
Now, download the compatible version of Skype for Windows 10 from a trustworthy source.
Install and open the application.
Sign in using your user id and password.
Make sure you keep your Skype updated all the time.
This will help you know if there is any update available for Skype or not.