Thanks for the feedback. The "Unable to process update" message is usually because the zip file is corrupt - and this almost always happens because the Flash Drive was removed without doing the "eject" procedure on your computer. Windows XP seems especially prone to this problem. Sounds like you got it all worked out though.
I tell a lot of folks that the only difficult part of the update procedure is saving the update file from your computer to the USB Stick. And that is difficult because the process is different for every computer / OS / browser. But once you've done it once or twice, and figured out the procedure for your computer, it's a piece of cake!
Thanks,
Walter