You're enjoying a leisurely afternoon of web surfing on your Mac. Suddenly, your YouTube video is rudely interrupted by an ominous gray and black screen.

"You need to restart your computer," reads the message, written in several languages. Behind it is a faint image of the power button on your computer. This is known as a kernel panic message. There are a couple of easily solvable reasons why this screen may have come up, but if the message continues to appear, you may need more in-depth Mac repair.

A kernel panic basically means that the system has encountered an internal error that it cannot recover from, but take a deep breath, because it's not always as bad as it sounds. In fact, sometimes it is a simple matter of removing an external device, or, most likely, making sure your software is up-to-date across the board.

First, try restarting your Mac with a Safe Boot, which you can do by holding down on the shift button as soon as you hear the start up tone. If the kernel panic message is not showing up when the computer is in Safe Mode, update all your software by clicking the apple icon, hitting "Software Update," and installing all available updates to your Mac.

Ideally, the software update will solve the kernel panic. If the screen doesn't appear again, it was probably just a software-related issue. There could, however also be an problem with your network, or even your wireless internet router, so checking on those can't hurt, either. If the screen continues to appear, contact your local Washington, D.C. Mac repair service.