FPS too low...

I do not know what happen to my computer, it has never happen before...
I have been playing GW with this computer for like 1 year or more...
The game suddenly gets very lag and I have found out that my FPS drops to 1-3 only...But then it returns back to normal after a minute or something like that. I have already updated my display card driver but it doesn't help...
Please advice...

Hmm... try reinstalling GW off the website, that seems to solve alot of problems that occur with the game. also, your specs might help.