I have no idea if this will work, but at least it can't hurt and is worth a try. Simultaneously hold down the C F O keys, then push and release the On key and see if the calculator boots into it's bios screen. If it does, then use the arrow keys to select the FLS utility, hit Enter, select the Format flash drive utility and hit Enter. This should recover the operating system unless it has been completely clobbered. Do a hard reset to get out of the bios utility and reboot the calculator normally.
As far as the firmware update, I did mine w/o any unzipping or whatever. I just highlighted the Prime name at the top of the tree in the Connectivity Kit with the Calculators tab clicked, right clicked on it, selected Update firmware at the bottom of the menu and hit enter. At first it failed because it was trying to update before the driver software was installed to treat the Prime as a disk drive connected to the pc, but it succeeded on the second attempt. At no time during any of this did I disconnect the Prime from the pc or turn it off.
After completing firmware update I noticed that it was the same version 2013 8 13 (5106) that was already on the calculator, so if you do get that far check your version first before attempting to do an update. According to Tim W, that is the latest available update, and it's just being sent to users, because it's now on the ftp site.
Edited: 9 Nov 2013, 8:27 p.m.
