Windows Vista On My Laptop.

[Niemster]

I've had my Sony Vaio for a little under 3 years now and havent had a single problem with it until a couple days ago when the laptop seems to freeze completely for no apparent reason. Especially when being switched back on from hibernate or from the energy saving mode. I go to click on the start button and open a document or click on an icon for the internet, a short while after clicking the whole thing freezes and i cant click anything or get to the task manager. There are a couple of lights on my laptop for battery, power and one that is usually flicking on and off which i assume is the processor (its always on when im loading up a new window), this goes blank to show nothing is being processed. The whole thing seems to just die on me. I am forced to switch off by holding down the power button which i don't feel to great about doing but there doesn't seem to be anyother way. I assume its not a virus but i suppose i can't be 100%. I run AVG free so i trust it isn't. It looks to be a windows problem or something along those lines. Any clues or do i take it down the sony shop for help?