Hi all
This is my fix working help for old HP 7475A plotter owners,under XP and VISTA with original driver:
Sorry my english is bad.

-No XP/VISTA driver on the internet,nothing.(the compatible(?) roland drivers i not tested)

This is a fix working alternative with original drivers:

-Buy correct HP-special cable for the plotter,or change it the standard cable.
see the correct pinouts contacts: http://h20000.www2.hp.com/bizsupport/TechSupport/Document.jsp?locale=en_US&taskId=120&prodSeriesId=25257&prodTypeId=18972&objectID=bpp01037#A0

-Install Microsoft Virtual PC 2007(freeware) (=virtual computer and virtual op system
under XP or vista)

-setup virtual pc(create virtual hard drive,create partititions,format this drive,set the virtual CD-ROM to the physical CDROM or set win98ME-boot image file,then boot up and install windows 98ME /from disk or image file)
-now complete the virtual pc,in virtual-pc setup change the used virtual COM or LPT ports to the real physical port

-ADD PRINTER and use the built in WIN98ME HP7475a driver

The old HP 7475A plotter and the original driver works fine under XP and Vista