I really don’t know why MSDTC caused such an error. I had this problem while deploying BizTalk solution. First, the error was Object refer null, then i re-deployed, the COM+ still appeared. I tried updating Windows by clicking the link http://update.microsoft.com/microsoftupdate/v6/default.aspx?ln=en-us.Check for updates. Then i restarted my computer, and the error went away.
If someone knows why i got that error, please let me know.