Shoutbox

I got a call off a friend, and she was having problems with her mouse..
It started when she booted up, and tried to open Internet Explorer. Apparently, her description was that the mouse wouldn't click anywhere (i assume she can move the cursor). It seems as if she can't click on any icons with effect, and it started when she booted up one day.
Any ideas on how to fix? (bear in mind she's female, and hasn't got a clue about computers)

EDIT: i think it's a regular plug&play mouse

Thanks loads.