My mac keeps restarting on it's own, is this virus related?

Question

I am using mac word to type up a document, and it keeps restarting (3 times). I read that macs can catch a virus but they do very little to them. I am not sure if this is the case, or something else is going on. Is there a cleaner, or virus scan that I can run on it? If so, does a mac come with this software? if not, can you guys please suggest something. no smart *** answers please. just save both out time and move on. thanks!

Answer 1

A computer restarting  on it's own is one of the symptoms of a virus infection but it can also be a dozen other things causing this problem.

Answer 2

This is NOT normal behavior.  The first thing you should do is eliminate PRAM and software problems.  First, find the OPTION, APPLE, P, and R keys and get ready to press ALL 4 down at the same time.  Push the power button and immediately hold down the 4 keys and keep holding them.  You will hear one startup chime, keep holding, you will hear another one, keep holding, and finally a third chime will bong and then let go of the keys.  It will startup normally.  Then, when the desktop is up, go to the GO pull-down menu and choose UTILITIES.  In the UTILITIES folder, open up Disk Utility and look for the second item in the left column (by default it is called Macintosh HD) and select it by clicking once on it.  Then, just look toward the lower middle of the window and click on Repair Disk Permissions.  Let it run and do its thing, then exit out of Disk Utility.  Once you're out, see if the machine is behaving itself.  

There is one more thing you need to do and that is to shut the iMac down and  reset the System Management Unit.  On your computer, it is pretty easy.  When the unit is shut down, unplug ALL cables from the computer (yes, the power cable, too) and wait 10 full seconds.  Then, get a hold of the power cord (that's already plugged into a live outlet strip) and insert the power cord while pressing the power button on the back of the iMac.  Once the cord is plugged in, you will need to push the power button again to start it up (it should not have started up when you plugged in the power while pressing the power button--if it did, pull out the cord after shut down and wait 10 seconds again and depress the power button just BEFORE you insert the power cord into the back of the iMac--keep it pressed until it is plugged in all the way).  

Now, when the computer starts up, immediately check for software updates by clicking on the blue Apple and selecting the second item in the list (Software Update).  Choose to download/install any/all updates available and restart if it asks you to.  Then, try the machine out and see if it still behaves poorly.  If it still shuts down, a new power supply or new logic board may be needed.