"...Make sure you've enabled remote access for the SQL server, made sure if you have a firewall on PC01 that it allows TCP port 1433 to pass, and that TCP/IP protocol is enabled on the SQL Server"

I have done all the above, I have even installed a port scanner on PC02 to check that PC01:1433 is open, which it is. By default SQL Server 2012 has TCP/IP enabled, and I have disabled all of the firewalls on both PC's, as well as AV too.