In your Windows computer you may see many problems while you are using some apps or programs. It is seen that sometimes when you want to have rest or want to go somewhere for sometimes, you usually put your computer on sleep mode so that the work will begin after sometimes without starting it on. But problem comes to you when the computer refuses to get into sleep mode and you get Sleep mode not working in Windows 8 problem. It is not a very critical issue but you should fix it as soon as possible. You can go with some manual or automatic way of error troubleshooting to fix the problem. For automatic fixing, you should download and install Advanced System Repair tool in the computer.