MS DTC requires that you authorize XA DLLs to limit the risks associated with using 3rd party XA Dlls in the MS DTC process.

When you upgrade to Windows Server 2003, all XA transactions are turned off to protect MS DTC against denial-of-service attacks.

To turn on support for XA transactions:

1. Start Component Services.

2. Expand the tree view to locate the computer that will have support for XA transactions (My Computer).

3. Right-click the computer and press Properties.

4. Select the MSDTC tab.

5. Select Security Configuration.

6. Under Security Settings, check the box for XA transactions to turn on support.

7. Press OK and OK.

You must create a registry Value Name for each XA Dll that you intend to use, and you must check that any 3rd-party installer created the necessary Value Name(s).

To create a Value Name:

1. Use the Registry Editor to navigate to:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSDTC\XADLL

2. For each XA DLL, add a Value Name which is the <DllName.Dll>, as a String (REG_SZ) data type, and set the data value to the fully qualified path to the file, as in <Drive:>\Folder\DllName.Dll.

NOTE: If you are using MS DTC on a cluster, you must create these Value Names on each cluster node.

NOTE: See the Value Name that Microsoft pre-created:

    Value Name     String Value
    mtxoci.dll         C:\WINDOWS\system32\mtxoci.dll