https://www.officelivesupport.com/error-0x80071a91/
Error Code 0x80071a91 error code is common for all the Windows Operating systems when you try to install the updates. It usually appears when Windows 10 or Windows 7 update system is broken or there are network-related glitches.
Usual causes for this Error Code 0x80071a91are communication failure over the internet with Microsoft update servers.
After that,
Disable the proxy internet connection and try again to install the update.
