Right clicking a file in explorer opens context menu with "Share with skype". This can be removed:
If Skype installed by download
1. Open regedit.
2. Open HKEY_CLASSES_ROOT\*\shell\ShareWithSkype
3. Delete 'ShareWithSkype' folder
4. done.
If Skype was installed from Store
1. Open regedit
2. Open Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Classes\PackagedCom\Package\Microsoft.SkypeApp_15.65.78.0_x86__kzf8qxf38zg5c\Class\{776DBC8D-7347-478C-8D71-791E12EF49D8}
3. Double click DLLPath
4. Put hyphen '-' at start of value.
5. done.