Solutions For windows 11 update Error code C80003FA :-
Here you have to follow steps as per causes of this Error code c80003fa in windows 11 update service client/
Firewall Check:-
First change your antivirus /firewall settings to OFF,
Windows Firewall is software that runs on your computer and provides protection against network attacks from the Internet or other computers on the network.
To turn off firewall,
Type in FIREWALL in start button search bar and open firewall application,
From the left side panel, find Turn windows firewall on /off option, as shown in pic,
Then choose to Turn off windows firewall in private and public network options.