This LW shutting down and loading up again sounds pretty much like a virus (please read here):
http://www.gnutellaforums.com/open-discussion-topics/41432-warning-viruses-network-you-should-aware.html

If you need free professional help to get rid of the culprit, go here and register for free:
http://norbiesworld.co.uk/computerhelp

__________________

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