If you are using Windows 10 in your computer then you have definitely prompted for the installation of Anniversary updates to your computer many times. But when you go to install the updates to the computer, you will see a very annoying and frustrated error issue i.e. installation error 0xa0000400 in Windows 10. You may get this error while you go to install the Anniversary updates to your Windows 10 computer. The Windows anniversary installation error 0xa0000400 comes to you due to incorrect registry entries or due to problem with the updating sites. You will not be able to update your Windows due to this error. So, it is very important to fix the issue with the help of the manual or automatic way of error troubleshooting. For automatic rectification of the error, you should use Advanced System Repair tool in the computer.