Some more information…
I uninstalled the Apple Devices app on my PC, and tried to restore the ipad using itunes. I can do a bit more now, but the process still ultimately fails.
When I start up itunes on the PC and plug in the ipad, it gives me a choice to either update or restore the device.
When I choose Update, it begins the process, but fails after a few minutes with an error (75) message. The update stops at that point.
When I choose Restore, it again begins the process, but when it gets to Restoring Firmware, then itunes stops working and shuts down. Nothing happens after that.
_ Pete