I was fixing a computer one time that had this issue.  Turned out to be a 
program running in the background, was a virus.  Norton removed it.  If you 
don't a purchased version of Norton, go to Symantec's website and run the 
free virus scan.  If it finds anything post what it says.  Also, if you 
could, download "HijackThis" and run the program, then post the log here, 
might be able to remove it without Norton if I can see what's running 
specifically.

"Randy" <mxrandynospam@aol.com> wrote in message 
news:77hDf.958$B_3.918@fe06.lga...
> Ever hear of this?  Not heat related.  Does it on AC or batteries.  Just
> freezes up then, after 20 seconds, starts again as if nothing happened.
> Happens every few minutes, often while finishing booting.  Can't observe 
> CPU
> useage because even that display stops working.  Doesn't crash---you don't
> have to reboot at all.  HD checks fine---no errors.
>
> Randy
>
>