If you use tabbed conversations in your Skype client you have the option to close current tab, or to close the tab group
You will probably choose one or the other depending on whether you are leaving for the day or just want to close out one conversation. But you have the option to “Always close all tabs” at the bottom.
Checking this may seem a great idea at the time and may serve you well. But what happens if you don’t want this behaviour anymore? Can it be undone?
Checking Skype options you can see there is an option to enable or disable tabbed conversations
You may think that disabling tabbed conversations and re-enabling will return the settings to their default, but this will not work.
To undo this setting memorisation you need to use the registry.
Open regedit and navigate to the following location
where “X” is your version number (15.0 for 2013, or 16.0 for 2016)
Edit the DWORD DontShowCWCloseTabQuery from 1 to 0
Now next time you try and close the tab conversation group, you will be prompted for the closure type again!