Would the LOL not signify humor? And if he did not recognize it as humor, then why agree? A response just trying to be nice, in my opinion, would be more like "You are not unintelligent. Sometimes it's hard to navigate these things..." Or something of that nature.
My view as it being degrading/rude is based off of the rest of the chat. Especialling in the beginning of the chat when I had explained that I had logged in to Norton Manager 3 times already this morning, and then again while I was waiting on him to review what I needed help with, and all times it failed to recognize any of my devices. To which his response was "Do you know how to log in to Manager?" and "Are you able to log in to Manager?". Questions which I felt the answer was obvious since I have alread explained I had logged in 4 times already. It just so happened that, on the fifth attempt after him asking me this, Manager finally recognized my device. Then he simply told me what link to click on to revoke the license for one of the old computers, after which I made that comment.
I'm not trying to be hateful. The entire conversation though just came across as rude.