Okay. I get it. You said "her", implying that females use computers too and that you're all for equality and women's rights rah rah rah. Go PC!
Except it's wrong. It should be "their computers". Or possibly "their computer", I'm a little hazy on which one is better (probably because I've been staring at it for too long), but "her computer" is flat-out wrong. Unless, of course, you're referring to one particular person's computer that everyone's going to use simultaneously. Which seems inefficient in a lot of ways.
This is where I fume loudly and wander off in a storm of irritation.
(Edit: Even better: just "computers". The "their" or "her" or "its" or whatever is just a noise word.)