Help with Conficker virus

Is there anything out there that can block the conficker virus from RE-INFECTING our end users and servers? Please help. Our network is falling apart because of this annoying virus.

We do the same thing every day, cleaning the same machines from this conficker virus, over and over, and over again for the whole week. We clean all our machines today and before the end of working hours the next day.. all our machines are infected again.

Is there something out there that can help BLOCK it from reinfecting our machines?