As others have pointed out, the "Vista" drivers (they are actually XP drivers not updated since 2007) will work under Windows 7. They will not work under Windows 8, however. Epson is promising Win 8 drivers for the 9600, but don't hold your breath. They had a similar promise listed for the 7600 for 3 weeks, then removed it from their web site. Now they say the 7600 will not be supported under Windows 8. This is outrageous for a "professional" printer. It is doubly outrageous because they never actually wrote a windows 7 driver. Had they done so, that would have worked in Windows 8. To not update drivers for a professional product in 6 years is unacceptable.
Let's remember that Epson makes their money on selling ink and paper, not on the printer itself. They are still generating revenue from selling 7600 inks, yet they won't support the printer. I have recently switched to 3rd party inks for the first time. So far, the results are great. I refuse to buy any more Epson supplies if they will not properly support their products. And when I do upgrade, there is a better than even chance that I will buy a Canon. In the meantime, I'm getting great prints from non-Epson ink that is half the cost of OEM.
I encourage all wide format printer purchasers to consider all their options before buying Epson.