Fastest copy to copy files over the network between Windows 7 PCs?

Hmmm. 10megaBYTES per second sounds like 100baseT throughput to me, not gigabit. Perhaps you should check your nic/switch settings? I'm using a gigabit netgear switch with jumbo frame support in windows 7.. I'm don't remember exactly offhand what kind of throughput i'm getting, but its SIGNIFICANTLY more than 10 megabytes per second.

Check each machine's network card settings and make sure the speed of the cards are both set to 1000Mb/Full Duplex. I have found that sometimes when cards are left on 'autoneg' they can seem to get confused and not agree on the fastest transfer mode.

As for type of transfer, when MicTech says FTP is simpler, I think what he means is as FTP transfer set up a separate transfer connection. The data transfers quicker because there is less overhead in the FTP protocol. The SMB protocol isn't famed for its efficiency, there is a lot more protocol overhead.

I think simplest way is FTP, because FTP is designed for file transfer :)

You can use some of free FTP servers for that.
https://superuser.com/questions/12869/best-opensource-ftp-software

And here is good article about home network and file transfers from Scott Hanselman
http://www.hanselman.com/blog/WiringTheHouseForAHomeNetworkPart5GigabitThroughputAndVista.aspx