Stop Process answering TCP Packets

The M$ "Remote Procedure Call" service uses this port. DCOM relies on that service. U might find this service in Service Manager.

Let me guess that U are using raw sockets in your program. I don't know what goals U want to achive, but for getting the total control over tcp connection servicing, U have to write your own kernel-mode driver and place it between the pure IP level implementation and the TCP level implementation of the kernel. I guess that the all windoze network-level implementation has a stacked architecture, thus it's possible to place your own intermediate level. I don't know much about Windoze network implementation, thus cannot point U in the concrete material. If U are still interested, I'd suggest to take a look what Windoze DDK says about programming of network drivers.