Rolling back to IE9 did allow Photoshop 4 to work again, but that caused problems with other programs, including my Norton.
Last month, my boot drive bricked on me, so I decided to do a clean install. After installing Win7 with all its upgrades, it wouldn't even let me install PS4. So, I reformatted the drive and started all over again. But this time, I unplugged the ethernet and wouldn't let Win7 update itself. I installed PS4 before installing any other programs. Then, I plugged the ethernet back in and let the OS do all of the updates it wanted, including IE10, and for some reason, my PS4 works fine. I don't understand it, but I'm happy.