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.
Have five year old Dell with files totaling about 30GB. Want to transfer music and photo files by using a cable - or networking, and feel I can figure this out. However, my question is this: How do you keep the bad files and junk from also migrating to your new computer? Would appreciate advice on this. Thank you. Victoria