Welcome to HP Forums @HP5740User,
Thanks for the post.
I understand that you are getting "HP Protected Cartridge Installed. Replace cartridge." message on your printer.
Not to worry, I will be glad to help.
Are you using the cartridges that were installed in any other printer?
Are you signed up for instant ink?
Are you using genuine HP ink?
If the cartridge was used on any other printer, the user has an option to enable cartridge protection. If it is enabled, you will not be able to use the cartridges on any other printer.
For an HP Forums port which explains this, please click here.
If you wish to disable this feature, you can follow the procedure mentioned below.
1. Open Devices and Printers Window from the Control panel.
2. Find your HP printer in the list and double-click it to open the Settings page.
3. Click the text for Estimated Ink Levels under the heading of Shopping Resources. This
will open the HP Toolbox window.
4. Click the tab for Cartridge Protection.
5. Click the radio button next to Disable HP Cartridge Protection.
6. Click the Save Setting button to save your new setting. Then, close the window.
7. You may need to remove and reinstall the cartridge for it to be recognized properly.
Let me know if this helped.
Chimney_83
I am an HP Employee