For the HP LaserJet M506 (white printer), check and make sure IP address 130.85.192.143 is still valid.

1. Make sure you login as administrator

2. Go to Start Menu/Devices and Printers/ and remove all invalid printer identities.

3. Navigate to this page http://h20564.www2.hp.com/hpsc/swd/public/detail?sp4ts.oid=7326623&swItemId=ds_139815_5&swEnvOid=4063 and download installer

4. Next run the program and click through the installer until you reach the "Connect the Product" tab
   
   

   Open

   

5. Next click on "Search using an IP Address" and enter the HP LaserJet M506's IP address.
   
   

   Open

   

6. You should get a page that looks like this. Click next and let the printer install.

7. Print test page then restart the computer.

For the HP LaserJet 200 color m251nw (black printer). The same information above applies, the IP address will be different: 130.85.192.166.

1. Navigate to this page http://support.hp.com/us-en/drivers/selfservice/HP-LaserJet-Pro-200-color-Printer-M251-series/5097632/model/5097639

2. Choose HP LaserJet Pro 200 color M251 PCL6 Driver with Installer and download

3. Follow above steps but be sure to replace IP address where different.

4. Print test page then restart the computer.