This service coordinates transactions between Microsoft Distributed Transaction Coordinator (MSDTC) and Kernel Transaction Manager (KTM). MSDTC performs the transaction coordination role for components, usually with COM and .NET architectures, and KTM prevents a series of database operations from occurring only partially, so either all occur, or all do not occur. These functions are used in features such as Transactional NTFS, which assures that file and directory actions are handled properly in the event of a crash or failure. If no applications or components of Vista EVER crash, it’s probably OK to disable this one, but if you value your data, you’ll want to keep it running.