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I understand that you are having issues after changing your router. Appreciate your efforts in connecting the printer to the network. Let’s first try to fix this issue using HP Print and Scan Doctor (PSDR). PSDR is an automated tool which can diagnose and resolve printing and scanning problems. Please go to http://hp.care/2bZ9w2q to download and run HP PSDR. Once you open the program, select your printer and click on “Fix Printing” to automatically diagnose and fix the issue.
If the issue persists, try the steps below and check:
Unplug the USB cable from the printer and computer if present.
Go to Control panel – Programs and feature – Select all the HP Photosmart printer entries and uninstall them.