Re: network printing garbage
First, which driver? PCL5e, PCL6, or Postscript? Or all?
Second: what programs are you printing from? If PDF's, and others, it will need the Postscript driver. Word, Excel, etc., will use the PCL5e/6 driver. The driver files you have may be corrupt. Delete them completely, and download from HP. Turn off firewall and antivirus for download and install.