I had the same call the other day!
I thought i'd have a giggle, so let him go through his spiel!
"sir, can you type this in the address bar, <a class="postlink" href="http://www.___________" onclick="window.open(this.href);return false;">http://www.___________</a>" "No i can't" i reply.
"well sir i have on my machine critical error messages from your computer, if you do as i say, i can fix it" "oh ok then, what do i do"
"Type this in your address bar <a class="postlink" href="http://www._______" onclick="window.open(this.href);return false;">http://www._______</a>""what address bar"
"on the top of the page""what page"
"on your computer""i don't have a computer"
"on your laptop then""i don't have a laptop"
"sir why are you wasting my time""hold on there's someone at the door"
"sir, sir, sir, sir,""yes"
"fuck you your mother has sex with goats""thanks, bye"