What? That dude? The same man who spent half the morning wandering around the office with nothing to do because his computer was broken, only to discover when IT finally arrived from Corporate that the monitor was off? That guy is telling you how to send an email? What?
The same woman whose resume advertised an “advanced” understanding of all Microsoft programs, but who asked you, privately, on her first day, “Um, how do I open Word?”
The only person in this entire office who knows how to use the internet is getting advice from the man who asks customers for their “email number?” He’s telling you how to do a Save As? You?
Wait. The woman who once had you completely confused by her complaints about the amount of time it took to move down from one line to the next in an email, who didn’t understand why you didn’t understand what she was saying, and who finally demonstrated how frustrating it was for her to hold the space bar until the cursor moved down two lines, and to whom, finally, you spent twenty minutes explaining the wonders of the “Enter” key.
You want to know how to be polite when people over 65 offer you computer advice?
You’re going to have to lie. Thank them for their oh-so-helpful expertise, assure them that you will come find them if you have aaaaaaaaany trouble, and then go back to your desk (laughing or crying, however you handle this kind of thing), and move on.