The fix to play the game without it freezing every two minutes
You don't need to disconnect from the internet.

Log in on a Windows account with Administrator permissions
Go to C:\Windows\System32\drivers\etc
Right-click the 'hosts' file, press properties > security
Click on your Windows username and press 'Edit...' to change the permissions.
Under Full control check 'Allow', and click 'OK' and exit.

Now open 'hosts' with notepad (not notepad++).
Add the following inside the text:
216.98.48.18 127.0.0.1
216.98.48.53 127.0.0.1
216.98.48.57 127.0.0.1
216.98.48.133 127.0.0.1
216.98.48.134 127.0.0.1
203.132.26.155 127.0.0.1
216.98.50.240 127.0.0.1

And click 'Save' or press Ctrl+S.
If it prompts you to "Save as..." you haven't properly changed the permissions.

This change does not harm your computer or cause conflicts in the future.
It fixes a bug where Assassin's Creed tried to connect to the Ubisoft servers, failing and causing the game to freeze.
Since their servers are down and their IP's have changed, this fix redirects the connections back to your own computer.