安装windows 10正式版后，最近的电脑每次启动总是会自动重启一次，重启时屏幕显示的信息是：

We couldn't complete the updates, undoing changes.

查看了下设置-》更新与安全-》更新记录，有一个更新有很多安装失败的记录。解决方法如下

原文：http://answers.microsoft.com/en-us/windows/forum/windows_10-update/cumulative-update-for-windows-10-for-x64-based/792cfa6a-c08d-4ddb-be99-71b440d51252?auth=1

THIS SOLVED IT FOR ME 

Reset Windows Update components and install the update.

I suggest you the following steps:

1. Press Start on the keyboard, type cmd in the search bar and then select “Command Prompt (Admin)” from the menu.

2. Stop the BITS, Cryptographic, MSI Installer and the Windows Update Services. To do this, type the following commands at a command prompt. Press the “ENTER” key after you type each command.

   • net stop wuauserv

   • net stop cryptSvc

   • net stop bits

   • net stop msiserver

3. Now rename the SoftwareDistribution and Catroot2 folder. You can do this by typing the following commands in the Command Prompt. Press the “ENTER” key after you type each command.

   • ren C:\Windows\SoftwareDistribution SoftwareDistribution.old

   • ren C:\Windows\System32\catroot2 Catroot2.old

4. Now, let’s restart the BITS, Cryptographic, MSI Installer and the Windows Update Services. Type the following commands in the Command Prompt for this. Press the ENTER key after you type each command.

   • net start wuauserv

   • net start cryptSvc

   • net start bits

   • net start msiserver

5. Type Exit in the Command Prompt to close it.

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自己的总结是，现在windows10的驱动有些问题，我两台电脑的windows10都有这种更新安装失败，为此我每台电脑已经重装过系统至少3遍，最近一次安装是2015年12月，下载官方的最新镜像。但是每次开机还是会自动重启一次。这个问题只能等微软解决了，用久了还是觉得比win7、win8好用不少，先忍忍吧...