This Error Code 0x800705B4 is commonly caused due to the .NET framework installation failure.These are following ways in which you can attempt to correct this error.
Disclaimers: Before you attempt to fix an issue with the windows update, we highly recommend you to take a registry backup and create a system restore point as a precaution method.
This .NET Framework 3.5 for Windows 8 or Windows 8.1 won’t come with pre-installed .Windows 8, Windows 8.1 or Windows 10, and must be separately enabled to run applications that depend on it.
You can try these solutions to fix windows update error 0x800705B4 while updating/up grading:-
Perform a sfc scan so that you can fix potentially corrupted or missing files, most of cases this system file scan fix common issues with file system.
In the command prompt window, type SFC/SCANNOW and press enter,
