We had similar problems (for years), which is why we've started moving all apps to VFP8. Especially HP OEM printer drivers failing, and MS operating systems print spooler stopping etc.

One solution - install a Linux server with samba for server file sharing and CUPS for printing services. It won't crash, it won't lock up, and theres no limitations on the number of users...and its free.

The other solution is to use a "standard" MS Windows supplied printer driver as substitute for the OEM driver yopu may have installed with your HP printers - ie HP LaserJet Series II for most laser printers, DeskJet 670 etc for deskjet printers. This generally fixes the problem with drivers, but won't fix Microsofts flakey print spooler.

Hope that's useful, Matt.