The Change Mode button is unavailable in the Organization Properties dialog box after you upgrade Exchange Server 5.5 Service Pack 3 to Exchange 2000 Server or to Exchange Server 2003

You cannot change the operational mode from mixed mode to native mode in Microsoft Exchange Server 2003 or in Microsoft Exchange 2000 Server. When you view the properties of your organization in Exchange System Manager, the Change Mode button is unavailable. (The button appears dimmed.)

This problem may occur when the following conditions are true:

• Microsoft Exchange Server 5.5 was previously installed on your computer.
• You removed Exchange Server 5.5 from the computer, but some Exchange Server 5.5 components remain in the Active Directory directory service.

To resolve this issue, follow the methods below in the order that they appear in. If Method 1 does not resolve the issue, follow the steps in Method 2. If Method 2 does not resolve the issue, follow the steps in Method 3, and so on.

Method 1: Manually delete the Site Replication Service from Exchange System Manager

You may be able to resolve this issue if you delete the Site Replication Service (SRS). For additional information about how to manually delete the Site Replication Service from Exchange System Manager, click the following article number to view the article in the Microsoft Knowledge Base:

Method 2: Use the LDP tool (Ldp.exe) to edit attributes

If you cannot remove the SRS, use the LDP tool to remove the following attributes:

• msExchLegacyAccount
• msExchLegacyDomain
• msExchEncryptedPassword

Additionally, use the LDP tool to edit the msExchAdminGroupMode attribute by removing its value in the Edit Attribute box.

To edit these attributes, follow these steps.

Warning If you use the ADSI Edit snap-in, the LDP utility, or any other LDAP version 3 client, and you incorrectly modify the attributes of Active Directory objects, you can cause serious problems. These problems may require you to reinstall Microsoft Windows 2000 Server, Microsoft Windows Server 2003, Microsoft Exchange 2000 Server, Microsoft Exchange Server 2003, or both Windows and Exchange. Microsoft cannot guarantee that problems that occur if you incorrectly modify Active Directory object attributes can be solved. Modify these attributes at your own risk.

1. Start the LDP tool.
2. Click Connection, click Connect, and then click OK.
3. Click Connection, click Bind, type the administrator's password in the Password box, and then click OK.
4. Expand the CN=Configuration, DC=Domain, DC=com container.
5. Expand CN=Services, and then expand CN=Microsoft Exchange.
6. Expand CN=Organization, and then expand CN=Administrative Groups.
7. Right-click the administrative group that you want in the left pane, and then click Modify.
8. Make sure that the following text appears in the title bar of the Modify window:
   CN=Administrative Group,CN=Administrative Groups,CN=Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=Domain,DC=com
9. Type msExchLegacyAccount in the Attribute box, click Remove, and then click Enter.
10. Click Run to remove the attribute.
11. Repeat steps 8 through 10 to delete the following attributes:
    • msExchLegacyDomain
    • msExchEncryptedPassword
12. Make sure that the following text appears in the title bar of the Modify window:
    CN=Administrative Group,CN=Administrative Groups,CN=Organization,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=Domain,DC=com
13. In the Attribute box, type msExchAdminGroupMode, and then click Replace.
14. Type 0 in the Value box, and then click Enter.
15. Click Run to reset the administrative group.
16. Quit the LDP tool.

Method 3: Remove the SRS from Active Directory

To remove the SRS from Active Directory, follow these steps:

1. Start the ADSI Edit tool.
2. Expand Configuration Container, and then expand CN=Configuration, DC=Domain, DC=com.
3. Expand CN=Services, and then expand CN=Microsoft Exchange.
4. Expand CN=Organization, and then expand CN=Administrative Groups.
5. Expand CN=Servers, and then expand CN=Server.
6. Right-click CN=Microsoft DSA, and then click Delete.

Method 4: Edit the msExchMixedMode attribute

To change the value of the msExchMixedMode attribute to False, follow these steps:

1. Start the ADSI Edit tool.
2. Expand Configuration Container, and then expand CN=Configuration, DC=Domain, DC=com.
3. Expand CN=Services, and then expand CN=Microsoft Exchange.
4. Right-click CN=Organization, and then click Properties.
5. On the Attributes tab in the Select which properties to view box, click Both.
6. In the Select a property to view box, click msExchMixedMode.
7. Click Clear.
8. In the Edit Attribute box, type False.
9. Click Set, and then click OK.
10. Quit the ADSI Edit tool.

For additional information about how to prepare a mixed mode organization for conversion to native mode, click the following article number to view the article in the Microsoft Knowledge Base:

The ADSI Edit tool is included with the Microsoft Windows 2000 Support Tools. For additional information about how to install the Windows 2000 Support Tools, click the following article number to view the article in the Microsoft Knowledge Base: