Promote that man to second line
"Kevin" showed great customer focus and dedication going through that process to help the user long after he should have gone off shift. That's a very admirable trait.
It shouldn't have taken him that long to realise that this was a communication problem not a "stupid user" problem even though the user was stupid. Nor was it a particularly difficult technical issue.
Nor, in fairness, did he log the call, shake his head, declare the problem to be beyond his ability to fix "sounds like a CPU nanometer core misalignment problem to me, I'll need to escalate to second line who'll be there in the morning kthxbye" like some people I've worked with have done.
Helldesk most certainly wasn't the role he was best matched with, just as I expect it wasn't for most of us who started there. If I were "Kevin"'s boss I'd have written up a good report and recommended a promotion to a second line break/fix team.