i have windows

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Your GFX card needs to support pixel shader 3.0.

pixel shader?

Yes, pixel shader 3.0.
You can see that if you get your video card's statistics.

ok ty bro

i have a mac os x 10.3.9 and toribash 3.31 but whenever i turn on shaders it doesnt work help me

Update your Toribash to 3.72 for mac here.
Then update your GFX card's driver to the latest.
If it dosent work then your GFX card dosent meet the requirements.

Nope, your Gfx Card needs to support Shaders 2.0. It's enough, but you might be unable to activate extra options.

i cant get 3.72 on my computer i need mac osx 10.4

It's pixel shader 2 for normal shaders ;)

Shader 3 is for cellshading (not available ATM)

Macs need an Intel 950 or better for shaders. You can check what you've got by clicking the lill' Apple on the menu bar, select 'About This Mac' & then the 'More Info' button.

Check the FAQ's shader thread for more information.