My spywareguard caught this Evil Thing trying to change my IE settings! But when I click to Remove the BHO.. it just keeps on popping up the same message and is not getting removed

I used AVS virus and Spysweeper and AVS spyware and Adaware but this Thing is not going away!!! I found this nasty thing as stated in Spywareguard but I can not delete it.. it says it's being used right now.. How do I get rid of this please?
Here's the error message:
The following BHO has been added to your system? {13ef2b--4ab6-bb7d-4126b181c517
File Location: c:/Windows/systerm32/pmkhe.dll
I found the file.. now what? How come my software protecters didn't get rid of it? It's making my internet very slow and brings up ONE trick pop up that my computer is running slow and to download this malaware software crap

and when I go to websites.. i can actually see the URL on the bottom accessing my browser info help! Thaqnks in advance!