Hi john_rylatt,
Welcome to the HP Support Forums! :) I understand you are getting an error message that your print drivers for your HP Deskjet 930c are either corrupted or missing.
I would like you to run the HP Print and Scan Doctor- It was designed by HP to provide users with the troubleshooting and problem solving features needed to resolve many common problems experienced with HP print and scan products connected to Windows-based computers.
If you are given the option to uninstall and reinstall using the PSDR, please do. Let me know the outcome. I will watch for your reply.
Thank you,