WNR2000v4 N300 Firmware Update Problem- "The Selected disc image file isn't valid"

This time when I plugged in the router address it brought me to the Netgear genie which gave me the option to do the firmware update. I accepted and it went through a 3 minute process that terminated with disconnect from the internet. To get back up I had to do a factory reset of my router and couple reboots of my PC. Finally back up and sufficiently rattled by the whole experience that I'm just going to let it be...  Thanks again for your help.