Deleted IO8211Family.Kext (Help)

Hello, I have MacBook Pro Mid-2010

(Intel Core 2 Duo 2.66GHz, 4GB RAM, 320GB HDD, Mac OS X 10.8.2)

I am having Wifi problem since one month which I am trying to figure out.

I tried multiple solutions. None of them worked, today I tried solution...

I found a solution on internet to delete .Kext, So I deleted IO8211Family.Kext from ~/System/Library/Extensions/. But unfortunately this method didn't

Worked too, So now how can I restore my .Kext file back ? I also rebooted my MacBook, But that didn't create new .Kext.

So can anyone guide me how can I Restore that file back or Is it OK if the file is missing ?

Thank You.

Hoping someone reply quick.