I looked up instructions for your specific device. I found this information in a PDF file, converted to HTML for easier pasting:
Go to Start > Printers and Faxes.
Click on Add a printer.
Click Next.
Select Local printer attached to the computer. (Deselect Automatically detect and install my Plug and Play printer if it has been selected.)
Click Next.
Select Create a port: and from the pull-down menu select the correct port for your printer. (Most users will want to select Standard TCP/IP Port, as shown in the illustration.)
Click Next.
The Add Standard TCP/IP Printer Port Wizard window opens.
Click Next.
Enter the IP Address of the DI-604UP (default: 192.168.0.1) in the Printer Name or IP Address field. Add a name to the router IP address to differentiate it from other devices in the Port Name field.
The Wizard requires additional information to complete the process. In the Additional Port Information Required window, select the Custom radio dial and click the Settings button.
In the Configure Standard TCP/IP Port Monitor window, first select the LPR radio dial in the Protocol section.
Next, add a Queue Name, such as “lp1.”
Click OK.
The Wizard will return to the Additional Port Information Required window after the settings have been entered in the Port Settings tab on the Configure Standard TCP/IP Port Monitor window.
Please confirm the printer port information.
Click Finish.
Select and highlight the correct driver for your printer. (If the correct driver is not displayed, insert the CD or floppy disk that came with your printer and click Have Disk.)
Click Next.
At this screen, you can change the name of the printer (optional).
Click Next.
At this screen, you must enter a share name if you want to share the printer with other network users.
Click Next.
At this screen, you have the option of entering a location and description of your printer.
Click Next.
Select Yes, to print a test page. A successful printing will confirm that you have chosen the correct driver.
Click Next.