Laptop turns off with no warning

by lisahp on Wed 14 Jul 2010, 7:36 am

Hi
My laptop keeps turning off with no warning. I have to re-start it and there are no error messages when it comes back on.

I am running XP Service Pack 2

It has done this randomly in the past, but within the last two days when I am running Malwarebytes or Avira Antivirus it turns off in the middle of the scans. It also makes a horrible high pitched noise when it does, if that is of importance.

Any help is appreciated.
Thanks!