COM+, DTC, and 80070422
One of our "packaged" software bits that accesses my servers is going through an upgrade right now. Apparently this software requires DTC to be installed on my SQL Server, and able to accept remote connections. So I look up how to do that in the knowledge base:
http://support.microsoft.com/?kbid=555017
And immediately hit a roadblock. The DTC components aren't showing up in my Component Services console. The entire console's acting weird (well, weirder than usual) and when I go into the console and click "Options" it insists on having a timeout entered, and when I enter one, close the box, and go back, the setting's gone again and I'm required to re-enter it. Lots of weirdness, and no DTC tab. If you open the COM+ folders, you immediately get error 80070422.
After a lot of searching I was looking through the Services listing on the box (after restarting DTC for the twelfth time) and saw that "Com+ System Application" was disabled. I set it to manual, rebooted the box (test server) and everything started working.
So, if you're trying to follow those instructions and discover that the Component Services tool is acting odder than usual, make sure that service isn't disabled.