So my Mother calls me up one day:
Mom: This computer your friend sold me is full of viruses!!! (No hello, how are ya, nothing)
Mom: It stopped working! It has to go back to the shop!!!
Mom: Now I have to bring in the peripherals too! This is INFECTED!! It's garbage!!
Me: Wait. The what?
Mom: The printer, the mouse thing, the keyboard, all of it's infected!
Me: No, that's not...
Mom: And the new keyboard and mouse were from the GOVERNMENT so we know it's not infected, it's your friend's computer that's the problem!!
Me: Do you mean the new wireless keyboard and mouse your stepson gave you?
Me: What exactly was the problem? How did you know it was a virus?
Mom: I turned on the computer, it started up but then nothing happened, I couldn't get it to do anything.
Me: Anything how?
Mom: The thingy wouldn't go.
Me: The what? The mouse?
Mom: Yes. the mouse thing didn't go, it froze because of the virus.
Me: Did you check the batteries?
Mom: Batteries? Why would it need batteries? The last one didn't need batteries!
Me: The last one plugged in to the computer. This one runs on batteries, not magic.
Mom: Well, this is going to cost me a fortune isn't it?
Me: Probably. Please, don't do anything with the computer without checking with me first.*
Five minutes later:
Friend: Hi, uh,...
Me: Let me guess, the batteries in the mouse were dead.
Friend: How did you know?
Me: It took twenty seconds.
Friend: We have to charge her a diagnostic fee and charge for the batteries.
Me: I told you not to sell her a computer.
Friend: But we're a computer store.
Me: And I told you not to sell her a computer.
* Last time was "You're computer Is infected! Send You're CC to XXXX and We'll fix it!!" and she did. And then blamed me because I should have warned her about pop-up spam.