Restoring an AWS instance from an AMI stuffs up SIDs, which stuffs up a lot of security settings, MS SQL logins, MS DTC and a dozen of other things. Reconfiguring them by hand defies the purpose. It’s easier to fix the SID to make it the same as in the original machine when everything was configures to a working state.

Warning: messing up with SID is no joke.

You will need Sysinternals Suite, if you don’t have one.

Unzip, install, find psgetsid.exe and run it from a command line. Save the long ID it gives you in a file.

Use this saved SID in newsid.exe after restoring the image.

Using the same SID on multiple AWS instances will make them identical. It’s only good if the machines are part of an application cluster and share resources the same way. Works for me.

Every time you bundle up a windows machine on Amazon Web Services (AWS) it runs through sysprep and changes machine Security Identifier (SID). When the machine is back up after the bundling job all the user IDs are stuffed.

In particular MS SQL records user SIDs. It may be impossible to log in to the SQL server if you don’t have mixed authentication and sa account set up.

The other annoying thing is MS DTC error starts popping up when the SIDs change.

Resolution

Create MSDTC-fix.reg as follows

Windows Registry Editor Version 5.00

[-HKEY_CLASSES_ROOT\CID]

Run the following commands from a batch file or command line:

msdtc -uninstall
regedit MSDTC-fix.reg
msdtc -install

No need to restart. MS DTC should be up and running.

The Distributed Transaction Coordinator (MSDTC) service is a component of modern versions of Microsoft Windows that is responsible for coordinating transactions that span multiple resource managers, such as databases, message queues, and file systems. MSDTC is included in Windows 2000 and later operating systems, and is also available for Windows NT 4.0.

MSDTC performs the transaction coordination role for components, usually with COM and .NET architectures. In MSDTC terminology, the director is called the transaction manager.

Steps to configure DTC for EF:

1. Start Microsoft Management Console (mmc): Start Menu -> Run -> write mmc
2. Choose a Component Services snap-in

XP:

3. Go to Computers->My Computer

4. Right click on My Computer->Properties->MSDTC tab

5. Click Security Configuration

6. Make sure Network DTC Access is checked. In the Transaction Manager Comunication Group Box check “Allow inbound” and “Allow outbound“.

7. Click OK on both windows and you are done.

Vista:

3. Go to Computers->My Computer->Distributed Transaction Coordinator

4. Right Click on Local DTC->Properties->Security tab

5. Make sure Network DTC Access is checked. In the Transaction Manager Comunication Group Box check “Allow inbound” and “Allow outbound“.

6. Click OK and you are done