Computer crashes when I run norton

Ok, so recently my computer has started crashing when I try and run the virus scan (I have Norton anti-virus, which is less than a year old). I have managed to narrow it down; the computer crashes when the scan gets to the Java folder in Common Files. The computer just turns itself off, regardless of whether I am working on it or not.

Any insight to this problem would be great, since I am utterly computer illiterate and have no idea what the implications might be.

Thanks.