Windows NT 4.0 Service Pack 4 has superceded all DTC hotfixes.
You can obtain this service pack as well as any subsequent
Service packs at the following location:

http://www.microsoft.com/ntserver/nts/downloads/default.asp

Installing the above service pack is the recommended upgrade
approach for systems currently running the Windows NT 4.0
Option Pack. If you are not running the Windows NT 4.0
Option Pack or can not install Windows NT4 Service Pack 4
for any reason, the DTC stand alone setup program is
available at the following location:

ftp://ftp.microsoft.com/bussys/distapps/MTS/Public-Fixes/usa/DTC/SvcPack