By default, Skype starts when Windows does. If you don’t use Skype on a frequent basis, you are wasting resources by having it run when you don’t need it. To prevent Skype from starting when Windows does, follow these steps:
1. Double-click on the Skype icon in the notification area next to the clock on the taskbar.
2. Click Tools and select Options.
3. In the left pane, under General, click General Settings.
4. In the right pane, uncheck the Start Skype when I start Windows checkbox.
5. Click the Save button.