MS DTC then goes through a two-phase commit protocol to get all of the enlisted resource managers to commit. The two-phase commit protocol ensures that all the resource managers commit the transaction or all abort it. In the first phase, the MS DTC asks each resource manager if it is prepared to commit. If all participants say yes, then in the second phase MS DTC broadcasts the commit message to all of them. If any part of the transaction fails, if a resource manager fails to respond to the prepare request, or if a resource manager responds no, then MS DTC notifies all of the resource managers that the transaction aborted.
Transaction managers are a key part of most database systems.
Transaction managers are also an optional part of some operating systems. So, Microsoft implemented transaction management software for both Microsoft Windows 95 and Microsoft Windows NT operating systems. Combining the transaction concept with COM required innovation. Traditional transaction systems required considerable skill to install and manage. The challenge of integrating MS DTC with Microsoft's operating system was to automate installation, management, and use.