If that doesn't help follow this step by step instruction. Some steps may be slightly different as it was written for Vista but should apply to Win7 just the same.
1. If your printer is connected to your computer, disconnect it.
2. Click on the Start menu.
3. Click on Control Panel
4. Click on the Hardware & Sounds control panel.
5. Click Printers.
6. Click "Add a Printer"
7. Click "Add a Local Printer"
8. Check off the "Use an existing port" check box.
9. In the list entitled "Use an existing port" choose "LPT1: (Printer Port)
10. Click on the "Next" button
11. Choose "HP" as the manufacturer from the list of manufacturers
12. In the printers list that shows up, choose "Deskjet 5600"
13. Click on the "Next" button
14. In the text box called "Printer name" type "Deskjet 5850"
15. Wait for the computer to say that the printer has been successfully added.
16. Connect your printer to your computer (i.e. connect the cable to the USB port at the back of your computer.
17. A "Found New Hardware" screen should show up. Click Cancel on this window. (if it keeps showing up, just keep on clicking cancel until no more windows pop up)
18. Go back to the printer folder (i.e. the one where you clicked "Add a Printer"
19. Right Click on "Deskjet 5850"
20. Click on "Properties" in the menu that popped up.
21. Select the "Ports" tab.
22. Change the port from "LPT1" to "USB"
23. Click on the "Apply" button.
