If your computer is having problems finding and installing operating system updates, try using the Windows Update Troubleshooter to fix the problem. It makes sure that your computer is connected to the Internet, and checks to see whether your network adapter and Windows Update services are running correctly.
同时按下Win键+X，选择命令提示符（管理员），然后输入以下指令(也可以右键复制粘贴）：
Dism /Online /Cleanup-Image /CheckHealth
Dism /Online /Cleanup-Image /RestoreHealth
原文：http://www.cnblogs.com/linr/p/4691095.html