Acer 5920 laptop keeps freezing after a few minutes

I am having problems with my Acer laptop as it has recently begun to freeze; i'm using Windows Vista. It keeps freezing after about 7 minutes or so when playing a video. When left idle, it still does the same after about the same time period. Often when it freezes, it just shuts down and restarts, sometimes also displaying a very quick shot of a bluescreen with error commands listed before it shuts off.

I've gone into safe mode (incl. the option of networking) and it works fine and dosen't shut down or freeze up in anyway. I know this is a very common problem with people having similar problems. Sounds like virus, trojan or some kind of confliction/malfuntion in software/hardware, but i'm not sure. I was thinking of doing a reformat but need an opinion.

Any help would be grateful

 

Recovery or a clean install is a good solution.
You can off course try to find the cause on your own but it often takes more tome than a clean install.

EDIT: You can use msconfig to disable some apps from startup and check if when these are not launched notebook works fine- any third party app including anti-virus, firewall and so on. You can test several of those. If it doesn't help it's probably one of Windows' own services that causes it. IN such a case go back to plan A- re-install.

 

Also, try booting (through the F8 menu) with option "Disable automatic restart on system failure". This should let you write down the error code, which can then be Googled.