Computer Crashing / WoW Lagging

[dpeace]

I have two main problems with my computer at the moment, both of which im puzzled by and could do with some assistance. The first is, my computer is having random crashes, i'm not particularly sure what makes it freeze but this morning it froze twice within 2 mins of entering Firelands, after it had been fine all morning, after the second time of restarting my computer i didn't open up chrome and it didn't crash. Not sure if it was luck of coincidence. The other issue is when my friends log in and out of WoW, the game freezes for about a second before resuming to normal game play.

My PC Specs

CPU: i7 860 2.8Ghz Quad
GPU Sapphire HD 7850 2GB
Ram: 8GB
Mobo: Gigabyte P55-UD4P
PSU: Corsair 520W

I'm certain my graphics drivers are up to date, re-installed them 2 days ago. Also on a side note, if i have a video in chrome playing or a livestream directly behind WoW, I find WoW to lag slightly and drop a lot of FPS.

I think my problem is either software or my graphics card, but i'm not entirely sure. Hence was wondering if anyone else has any suggestions, ideas, etc.

Thanks

[janecristy]

My computer also blue screened yesterday and i have to call our computer technician to re-install XP window. It was running well before, I do not understand what happened to it. Our technician said its RAM went out of order which he replaced with a new one. It really creates stress when it used to go out of order.