In some environments today are still the older HP DesignJet models in use.How to print from Windows 7 (64 bit) using a Windows driver to an "old" HP DesignJet 600?
You can use the following printer driver:
HP Designjet HP-GL/2Driver for Windows Server 2003 x64 Editions, Windows XP Professional x64 Edition and Windows Vista
http://www8.hp.com/us/en/support.html