Set up a folder on each of the systems to have sharing enabled (right-click on the folder, under properties, sharing).
Then open up explorer and in the address bar type \\pcName, where pcName is the name of the pc you want to connect to (if you don't know the name you can find it by right-clicking "MY Computer" -> Properties -> Computer Name). Then copy files to and from the shared folder you created.
If the pcName doesn't work for you then use \\pcIPaddress instead, where pcIPaddress us the IP for the pc you want to connect to. You can find this by Start->Run->cmd and type "ipconfig /all" (no quote marks).