Windows Update error during installation - Code 80073712

[mlazzarotto]

Hello,
my system is a Dell Precision T1700 with Windows 7 x64 Pro SPI1 with Symantec Endpoint Protection as AV.

It's a couple of weeks since I have a problem with 3 updates.
The updates are the following


This is what I tried so far:

• Sfc /scannow
• Check disk
• System Update Readiness Tool
• Windows Update reset as from here

The WU diagnostic found that something is wrong:


This is the error I get every time:


Here you can find the logs of Windows.