13-20 FPS on World of warcraft. please help!

ok so i played World of warcraft and its doing ok for the first few minutes. but after a while the game starts to get choppy. i look at the fps and it went from 30 all the way down to 20 or 19. i cant even move for 5 seconds smoothly! i have windows 7 HP 2509m
and i have 8.00 GB of RAM (at least i think when i checked the computer properties) and an ATI type Graphic card.
System specs:
Manufacturer: Hewlett-Packard Company
Model: HPE-257c
Processer: Intel(R) Core(TM) i7 CPU 860 @ 2.80GHz
2.80 GHz
Installed memory (RAM): 8.00 GB
System Type: 64-bit Operating System
Pen and Touch: No Pen or Touch input is available for this display
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Please help! i want to be able to play World of Warcraft smoothly again

Bradleymee, welcome to the Seven Forums.

Let's start with making sure you have the latest driver for the video card and not the year and a half old version that HP has available,

http://www.sevenforums.com/graphic-cards/1810-latest-amd-catalyst-video-driver-windows-7-a.html

Next according to the specs for that computer,

HP Pavilion Elite HPE-257c Desktop PC Product Specifications HP Pavilion Elite HPE-257c Desktop PC - HP Customer Care (United States - English)

for the ATI card it came with the HD 5570, which is at the low end of the scale for video cards. With that card make sure you're running at a mix of medium and/or low settings in game.

Disable shadows.

FPS ingame will always fluctuate (WoW)...depends a lot on where you are and whats happening...You can "Disable Shadows" as Schroff87 said above and also disable all the effects in graphics options. WoW normally detects your hardware and auto configures settings so it should be close to anyways. Try disabling Vsync,enable hardware cursor.

Update Sound and Graphics drivers.

Your FPS will drop in capital cities with a high player density e.g Origrimaar,Stormwind, and also in Raid situations, due to all the whizz bang spell effects etc tho Internet speed has more of an effect in dungeons re lag to the point of being DC'd (used to happen more in the older 25man raids/World Boss encounters.)

Cheers