The default tendency in Microsoft Skype is to startup automatically with the computer and keep running in the background, always available and waiting to be used.
While this setup is designed for convenience, it can lead to unwanted resource usage by the Skype App on your computer, if you are unlikely to use Skype for most part of the day.
In such cases, you can prevent Skype from running in background by using Skype Settings and also by going to the Setting App on your Windows computer.
Stop Skype from Running in Background
You can find below the steps to prevent Skype Desktop App from running in Background by using Skype Settings and also by using the native Settings App as available on a Windows computer.
Additionally, you can also find the steps to prevent the Skype preview App from running in background.
1. Stop Skype Desktop from Running in Background
Once you download and start using the Desktop version of Skype, it will keep you signed-in and continue running in background, even after you close the App window.
1. Open Skype Desktop App > Login-in to Skype using your Microsoft Account.
2. Once you are logged-in, click on 3-dots icon located in the top-menu bar and select Settings in the drop-down menu.

3. On the Settings screen, disable both Upon closing, keep Skype running & Launch Skype in Background options.

Note: Disable Automatically start Skype option, if Skype is not your go-to App and also if you do not want Skype to startup with the computer.
4. Restart the computer to Apply this change.
After this, you should no longer find Skype Desktop App remaining active after being closed and continuing to run in the background.
2. Stop Skype Desktop from Running in Background Using Settings
You can also stop Skype Desktop from running in background by using the native Windows Settings App, as available on your computer.
1. Go to Settings > Apps (left-pane) > click on Installed Apps in the right-pane.

2. On the next screen, click on 3-dots icon located next to Skype and click on Advanced options.

3. On the next screen, scroll down to “Background App Permissions section” and set Let this App Run in Background to Never option.

3. Stop Skype Preview from Running in Background
Once you Sign-in to Skype Preview, it keeps you signed-in and keeps running in background. The only way to prevent Skype Preview from running in background is to Sign-out of Skype Preview.
1. Click on the Start button > scroll through the list of Apps and click on Skype Preview.

2. On the next screen, click on your Profile icon and select the Sign Out option in the menu that appears.

Once you sign-out of Skype Preview, you won’t find the App starting up with the computer and running in background.