I don't have any statistics on this, but most of the laptops that cross my desk have one thing in common: pressing the power button puts them to sleep (i.e. standby mode) instead of actually shutting them down.
That's pretty weird considering that many laptops also have dedicated "sleep" buttons. Fortunately, it's easy to change the power button's function, which can be programmed to make the laptop sleep, shut down, or hibernate. Here's how Vista users can make the change:
1. Click Start, type power, and then click Power Options.
2. In the lefthand sidebar, click Choose what the power buttons do.
3. You should see two pull-down menus alongside When I press the power button. One is for when the laptop's running on battery power, the other for when it's plugged in. Choose the setting you want for each scenario.
4. Click Save changes and you're done.
As you may have noticed, this screen also lets you change the functions for the sleep button (if your laptop has one) and for what happens when you close the laptop's lid. So you can kill a couple button-birds with this particular settings stone.
Special thanks to reader Jeff for suggesting this handy tip!