One way to solve the problem that the application pool is automatically disabled is

which is again a problem with the client Exchange server. Exchange 2003 and DC are the same server. After installation, you can't open the home page of the default website, showing Service Unavailable.

1. The first is to open the IIS Manager. Check the application pool, and sure enough "DefaultAppPool" has gone wrong. And not the usual stop icon.

2. Try to restart the "DefaultAppPool" application pool, but the pool was not long before the program and wrong.

3. It’s time to view the event log. The following types of logs were found

Event Type: Warning
Event Source: W3SVC
Event Category: None
Event ID: 1009
Date: 2008-6-24
Event: 16:12:33
User: N/A
Computer: MAIL
Description:
The process serving the application pool 'DefaultAppPool' terminated unexpectedly. The process ID is '3160'. The process exit code is '0xffffffff'.

For more information, see the Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

4. Will it be the default program pool problem? So, try to create a new program pool. Change the program pool of the default website to new. But the problem remains. A similar log appears.

Event Type: Error
Event Source: W3SVC
Event Type: None
Event ID: 1002
Date: 2008-6-25
Event: 14:17: 04
User: N/A
Computer: MAIL
Description:
Application pool 'AppPool #1' is automatically disabled due to a series of processes in the service pool for this application pool error.

For more information, see the Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

5. Look for the event log and another log caught my attention. As follows:

Event Type: Error
Event Source: DCOM
Event Category: None
Event ID: 10016
Date: 2008-6-24
Event: 16: 12:33
User: NT AUTHORITY\\NETWORK SERVICE
Computer: MAIL
Description:
Application - Specific permission settings are not COM server application (CLSID is
{A9E69610-B80D- The local activation permission of 11D0-B9B9-00A0C922E750}
) is granted to the user NT AUTHORITY\\NETWORK SERVICE SID (S-1-5-20). This security right can be modified using the Component Services Management tool.

For more information, see the Help and Support Center at http://go.microsoft.com/fwlink/events.asp.

6. A bit of a play. Take a look at what the CLSID is {A9E69610-B80D-11D0-B9B9-00A0C922E750}. Finally find it in the following registry key:

HKEY_CLASSES_ROOT\\AppID\\{A9E69610-B80D-11D0-B9B9-00A0C922E750}

7. The name is just "IIS Admin Service"

8. Ok, find what it is. Open "Component Services" from "Administrative Tools" and find the IIS Admin Service to see if the CLSID is consistent.

9. After confirming this, the next step is to add NETWORK SERVICE permission for it. Over.
A start and activate permissions, click "Custom"..

B. Add "NETWORK SERVICE" to the user list,

C. and give local launch and activation permissions, save exit.

To solve this problem.