Is this an apartment complex?
Setup sub-interfaces on the ERL "LAN port" with VLAN 1 and VLAN 10. Tag the internal LAN port from the ERL to your switch with both VLAN 1 and 10. On the switch, any device that needs internet access put on VLAN 1 and any device that needs TV, put on VLAN 10.
I...
Windows 7 never came on systems with DDR. Any OEM system with Windows 7 came with DDR2/DDR3 memory.
Also, I'm pretty sure that a piece of RAM for a system does not count under the OEM terms...
This not at all legal.