Hi again, Barkster!
Not having those files is positive 
When it comes to updating the firmware you can have a look HERE
Though remember to check that the firmware is compatible with your machine and compare the latest firmware with the one you have, also print out a config sheet before installing anything, just a tip.
Unfortunately I'm not working for Xerox, and I do not have the necessery tools to remote control your PC.
I do not know if Xerox is offering any kind of remote controlling, you can give them a call to see if they can help you with your problem, cause right now I cannot come up with anymore suggestions, sorry about that 
Best Regards
Kimzi
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