If you are running a web application using the original ASP technology on Windows Server 2003, you might get this error message once you upgrade to Service Pack 2: “New transaction cannot enlist in the specified transaction coordinator. [-2147168246]”.
The cause for this error is that MSDTC has a setting that requires authentication for distributed transactions, and the upgrade to SP2 might change the setting to required instead of none.
To fix this error, open Component Services and right-click on the My Computer icon and choose properties.
Choose the MSDTC tab and then at the bottom of the window click the Security Configuration button.
In this window, change the setting under Transaction Manager Communication to “No Authentication Required”.
This should resolve this error.
Note that if you have a firewall between the web server and database server then you should ensure that high ports are open between the two machines, along with RPC, as that could also cause the same error.