Michael E Wilber
It is obvious you will get offline your printer because your printer was connected with Windows 7, not 10. After installation, all the connection information removes with windows 7.
Now you have to install printer driver once again in windows 10 operating system. Once the driver would install need to make a connection between computer and printer.
Also, read more steps for HP printer installation from http://www.askprob.com/forums/topic/how-do-i-install-a-hp-printer-connect-new-hp-printer-with-my-computer/