How to Fix a Computer That Shuts Down After 15 Minutes
- 1). Click the "Start" Windows button, which is the green button located at the bottom left side of the computer's desktop.
- 2). Scroll through the menu that opens and select "Control Panel." This is usually located in the second column, sixth choice from the bottom.
- 3). Select "Appearance and Themes" from the window that opens. This will take you to another screen with a list of options. Select the "display" icon located at the bottom of the screen under the heading "or Pick a Control Panel Icon."
- 4). Click on the "Screen Saver" tab that is located at the top of the "Display Properties" window that opens after performing step 3. There will be a button label, "Power," at the bottom of the window; click this option.
- 5). Locate the "Settings for power scheme" section of the window and choose how much time you will allow your computer to sit before it shuts down. This can be as little as "After 3 minutes" or as long as "Never."
Source...