Want to increase you're in-game FPS?

[Ticks]

1) Disable or reduce the size of you're windows paging file.
The windows paging file uses you're hard disk as a kinda of virtual memory for reading and writing data during game play. Wow is very hard disk intensive and having to use the same hard disk to read and write virtual memory + load in game objects and items can cause you're FPS to suffer.
By simple removing OR limiting you're paging file in windows to Lower(256) Upper(256) you "MAY" notice a FPS increase depending on you're hardware.
"PLEASE NOTE: I don't advise you try this on systems with less then 2GB memory for Windows XP or 3GB memory for vista"

This is bad advice. You should learn how the Windows OS works before you give out advice.