Network Transfer very slow

I'm having a very strange issue here. I have two machines, one Windows 7 Professional machine as a client and an XP Pro machine that I'm using as a server (a game server). However, to install the files I need on the server, I have to transfer them from my client (thus switching roles, but don't let that confuse you). The only issue is, when connecting to the internet I get about 8Mb/s transfer rates on both machines, however, when using Windows Explorer to transfer files from the client to the server, the file transfer speed is about 100 bytes per second. Yes, bytes. But here's the kicker, when I use a program called TerraCopy to transfer files, it moves the files much faster (about 2-5MB/s). What on earth could this possibly be?

Oh yes, I'm using a wireless network, but I also tried using a different router and hard wiring both machines together and got the exact same result.

Turn off Remote Differential Compression.
Go to windows programs/features..then 'turn windows features on/off'.

Then wack that worthless 'option'.

Thanks, that seems to have worked! Transferring 467MB of information in 6 days wasn't my idea of fun. I probably could have used floppy discs and done it faster.