#5
Closing "Distributed Transaction Coordinator"
Distributed Transaction Coordinator service is enabled by default on a Windows 2000 server and opens TCP port 3372, and one TCP port higher than 1023 (1025 in my example).

Stopping this service closes two TCP ports:

C:\WINNT>net stop msdtc
The Distributed Transaction Coordinator service is stopping.
The Distributed Transaction Coordinator service was stopped successfully.