I wish I had a hundred dollars for every time I've solved this problem.

Your problem is nothing more than static electricity being generated as you move across the floor.  I'm willing to bet that you have plastic composition soles on your shoes and you are walking across a length of carpet.  The static electricity is generated as you walk.  The voltage you develop can become quite high ie. several thousand volts.  When you get near the computer which is grounded through the power cord a spark jumps from one of your fingers to the nearest piece of metal.  The spark can even go through plastic.  This can send a surge through the various circutes in your computer and cause it to reboot.

The cure is incredibly simple.  you can install a grounding strip on your desk which you would touch first or you can prevent the generation of the charge in the first place.  Get yourself a trigger spray bottle and fill it with a mixture of one half water and one half any liquid fabric softener.  Spray the carpet with this mixture and spray a wiping cloth with the mixture then wipe your keyboard, mouse and monitor with the cloth.  This will leave a conductive coating on the carpet and all plastic surfaces of the computer, which will help drain away any generated static.

it's just that simple.

Where I live we see this problem mostly in the winter when the air is extremely dry.

        The NOSPIN Group provides a monthly newsletter with great
       tips, information and ideas: NOSPIN-L, The NOSPIN Magazine
           Visit our web site to signup: http://freepctech.com