Error Code 0x800705b4 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.
Open Internet Explorer and click on Tools->Internet Options
Goto Connections and LAN Settings
Check to make sure the Proxy server is disabled.
The second case would be with your Antivirus. There are proxy settings enabled under your settings of any security programs that you may be using. If you cannot find the procedure to stop it, you can ask our techs on chat support to guide you.