If you reboot your system open Photoshop CS6 extended and open an image will Ctrl+P open Photoshop Print dialog. Here is a screen capture where I'm using Windows 7 Pro and Photoshop CS6 Extended subscription version 13.1.2. Using Ctrl+P CS6 Print Dialog opens. I can use its Printer pull-down menu and select any printer. Then click the Print Setting... button. The Printer setting dialog will open and I can set them.
Can you get it up the CS6 print dialog that is....
No, I am still get the same error from using the Ctrl+P shortcut.
EDIT: It may be worth mentioning that I can open the CS6 print dialog using the fix I mentioned in the original post.
Do you mean by changing you system default printer?
If you can get it up can you print to a different printer then you want to.
I know you wrote you install the print drivers again. Still what printer are you trying to print to. While I do not have the Epson attached to my workstation the drivers for it are installed and the printer setting dialog even seems to be communicate with the machine and the printer for the ink levels show on my workstation.
So IMO the printer device manager get involved. In your case what happens is Photoshop does not seem to see you system default printer when you set the printer you want to print on as the system default printer.