ITunes upgrade won't synch my iPhone

Ever since upgrading to 8.1.2 from 8.0, it won't sync. PC comes up and recognizes that a USB device is attached, and asks me to select the way it will be used (open with explorer, photo manager, etc.). It did NOT do this before. I tried Apple knowledge base solutions but no luck. Uninstalled Itunes, cleaned out installation files, got rid of mobile manager files, deleted drivers. deleted directories, etc all as per their instructions for this project, and then did an iTunes reinstall. No dice - iTunes still won't see the device, but will Windows still does.
Anyone have an idea how to do a hard-reset on the iPhone itself? Maybe that would work. I have a recent backup on iTunes that I could use to get it going again