Like I said, they can continue to use WP5.1, but the only way to print to a USB (most all printers now) printer, you will need to follow the instructions on how to loopback an LPT port to a USB port. Most newer computers don't even have LPT ports anymore. If you don't want to hassle with loopbacks, your only choices are to upgrade to the newest WP or use a new program for writing your documents that can understand USB devices.