Sally Newall-Sanderson, 44, had reset the laptop, deleted programs and called her broadband provider to try to get to the bottom of the problem.
The recruitment company director was on the verge of paying £600 for a new laptop when she took it to a repair shop.
But minutes later, she was left embarrassed when the shop called and told her what was wrong.
Sally said: “I didn’t know these buttons existed on the side of laptops.
“It was working fine and then suddenly it wasn’t.
“It was coming up saying I couldn’t get on the wi-fi.
“I started to panic because I’m not very good with computers. I’m not tech savvy at all.
“For about three or four days I was ringing the broadband company to see if there was something wrong with my broadband. How embarrassing.
“It got to about day four and I thought, ‘Right, I’m going to have to book it in somewhere’.
“As soon as I dropped it off and left, they rang me and had to explain it was just the wi-fi button on the side. All my laptops I’ve had, I’ve never noticed that before. I felt ridiculous.”
The mum of three, of Warrington, Cheshire, added: “I either caught it or maybe my little girl’s caught it messing around. My eldest son, who’s 15, he was like, ‘For God’s sake Mum, you’re so embarrassing’.
“But even they wouldn’t have known. We could have all been sat here for weeks trying to work the problem out.”
Writing about it online, Sally said: “Please put me out of my misery and tell me. Did you know about this switch?
“I’m not the only person that didn’t know about this, am I?”