The Windows Server 2003 Service Pack 1 Release Candidate is available for download at

The MSDTC changes are similar to the ones described at

In addition we have a new interface called IDtcNetworkAccessConfig2 that allows the management of the new configuration settings: inbound/outbound network access and the authentication level.

If you have questions or feedback about this Service Pack, you can post at the dedicated newsgroup:

Please try it out, we appreciate any feedback. Thanks!