I have three printers installed on this Windows Vista 64-bit machine, and they all operate normally with other applications. When I open a TIF or JPEG file in Photoshop, part of the time they open normally, and I can do print preparation and normal printing. Sometimes when I open a TIF or JPEG file, they open normally, but when I start to prepare them for printing (printer selection, etc.), a Photoshop CS4 message tells me that I have to install a printer first before I can do any printing-related tasks. It acts like there are no installed printers at all. Obviously I am not changing my printer hardware status between files that work and files that don't work.
I've been trying to compare the files that work normally with the files that don't work normally, and I haven't found the trend yet. If I try to recreate thousands of files that don't work normally so that they do print, that will be a monumental job.
---Robert---