Captcha Reader / Decoder

I'm looking for an OCR decoder with an accuracy of at least 60% (prefer higher) for the attached images. Delivery must be in form of a dll that's easily called / included in any .net / com projects. Would prefer source code to be included, but if the price is right, I'll let you keep that. I expect that I would be able to pass an image to the dll and get the text as a return, alternatively passing the url of the image and getting the text as a return would be acceptable. Please post any questions you may have.