When "File and Printer Sharing" is enabled between the two computers, the files don't simply go "rushing" to the other computer. You will need to copy the files from one machine to the other. In fact, if you don't have a large number of files to transfer, you might burn them to a CD or copy them to a USB flashdrive and transfer them over.

For file transfer options, see the link below:

How To Transfer Files Computer to Computer

In addition, to prevent possible network viruses from automatically moving over between machines, make sure the new computer has it's firewall enabled and an antivirus program updated and running.

Hope this helps.