Crashing Problem...

[Pheebs]

... Okay this is starting to drive me insane now!!

Our media poota downstairs is being a pain in the bum. Every so often it decides it wants to crash. It seems to be a regular thingy which happens when:

1. I open "too many" files in PS3 (not so regular until recently)
2. I look at FB photos and flick through them
3. Watching any videos (I would say only on youtube but then, I don't really watch videos anywhere else)

Normally it just reboots, sometimes though it will freeze and you will have to restart it.

All drives are only half full and defragged nicely. I canny see why there'd be a virus on the poota but am just grabbing AVG again to check it, but in all honesty it's been like this since we've built it (always had problems with videos... it's SUPER bothering me it's happening with pics now and my work).

Any ideas before I throw it out the window?

Thanks in advance