One option is to call MS. They are responsible for the product.

Another thing is how did you uninstall patches? Did you go to Control Panel==>Uninstall programs? If so, you need no button to uninstall KB's. There are no buttons for anything you want to uninstall. There is one uniform button that gives you a choice.

Another thing you can try is to find the directory where that KB is located. You can do it by Start==>Search window. Find the file location and delete it. You have nothing to lose at this stage.

And yet another option is to find the sucker in the registry and delete the key. That would be probably the safest bet but you better be careful and save the registry before doing any surgery.