If all PC's are on the same network, it can be done. Set one PC as the one to be shared. On that PC, open Windows Explorer. Either highlight the entire drive the files are on, or the individual file itself. No click on 'File' pulldown screen, click on 'properties', and then use the top tab 'SHARING'. Click on the 'sharing' button and give the resource a name. If using the entire drive, use a name like RobertPC.
Once this is done, select one of the other PC's. Edit the 'HOSTS' file. Add the IP address for the shared PC. Tab over and include the name(RobertPC) created on the shared PC. File the HOSTS file.
Go to Windows START, RUN, and enter \\RobertPC and press ENTER. This should open up a screen displaying the shared PC drive or file, depending on what you told it to share.