Captcha OCR

I am looking for someone to create an OCR that can decode the attached images with 90%+ accuracy. The delivery must be in form of either a) source code that can be compiled in visual studio 2005 (preferred), or b) a .NET dll that can easily be integrated in to my existing application. I, of course, need to be able to pass in the image (file location would be perfect). I do have one that works now, but it has intermittent issues (crashes on some pc's). The delivery must be solid, and not crash. The sooner the better. The attached file has a sample of 50 of the images in question.