Pavilion laptop fatally freezes randomly while working

[tozblom]

In the last several months my laptop has started freezing up while I am working.  It appears random and so completely freezes that ctl-alt-del cannot even be utilized... I have turn the laptop off by holding the "on" button.  In the last week this has happened 11 times, 3 times today alone.  My laptop is two years old, and I keep it very "clean."  There is plenty of HD space, lots of RAM, good virus control and regular clean-ups.  It is a Pavilion dv7t-3100 CTO, and I have Windows 7 OS.  It does not appear to be my internet provider nor browser, because it has frozen when not using the internet.  However, I work from home over the internet all day, so most of the occurances have happened while connected to my host work computer via gotomypc.  I get no error messages and the event log only shows the critical event caused by my doing a hard stop on my computer.  I have HP Total Care and they had me run a HD check, which it passed with no errors.  Their next suggestion was to return the laptop to factory settings by doing a reload of the OS, but that would be a LOT of work... reloading apps and files.  Any ideas anyone might have of what to check next would be greatly appreciated.