I have just got back to WoW after a month and a half, and my FPS is very low 15~, the game's performance is very bad.
The bad FPS start as I enter the world, no gradual decrease, also it is present in every place ive been so far.
I tried downlaoding the latest driver but it doesnt seem to help at all.

My graphic card is NVIDIA GEFORCE 8600GT,and 3G RAM.

Hi,

First of all please make sure that you have reset the game back to its default settings. With the game closed down please locate your World of Warcraft installation folder and delete the directories called WTF, Cache and Interface.

Restart the game and check to see if you have the same problem. If you're using Windows Vista, you may also find your WTF folder in the following locations:

C:\Users\Public\Public Documents\Blizzard Entertainment\World of Warcraft
C:\Users\Public\Games\Blizzard Entertainment\World of Warcraft
C:\Users/[username]\Appdata\Local\Virtualstore\Program files\World of Warcraft

(You may need to 'Show Hidden Files and Folders' to see the Appdata folder, this option can be found in 'Folder Options' in the 'Control Panel'.)