HOWTO: Troubleshoot Run-time Error '70' in DCOM Applications

• Microsoft Visual Basic Professional and Enterprise Editions for Windows, version 5.0

SUMMARY

Attempting to access a DCOM Server from a remote client application sometimes results in the following error:

   Run-time error '70':
   Permission Denied

MORE INFORMATION

Run-time error '70' is typically the result of a security or permissions issue. The following is a list of possible causes of run-time error 70 but is by no means a complete or definitive list.

DCOM Is Not Enabled

If the Server machine does not have DCOM enabled, client machines will receive run-time error 70 when attempting to access the server. This scenario applies to both Windows NT and Windows 95 servers:

1. On the Server machine, run DCOM Config (DCOMCNFG.EXE).

2. Choose the Default Properties tab.

3. Endure that Enable Distributed COM on this computer is checked. This value is stored in the Windows Registry at the following location:

         HKEY_LOCAL_MACHINE\Software\Microsoft\OLE
   

The Client User Does Not Have Sufficient Permissions

If the client user does not have the correct permissions, access to the DCOM Server can be denied. There are several steps to take in order to ensure your client has valid privileges.

If the Server is Windows 95:

1. Run DCOM Config.

2. Select the DCOM Server application from the list of available applications.

3. Select the Properties button, or double-click the DCOM Server application in the list.

4. Test the server with "Default Access Permissions."

   If run-time error '70' still occurs, the default access permissions are restricting your user. If this is the case, then modify the Default Access Permissions from the Default Security tab in DCOM Config. Grant the client user access permissions. If run-time error '70' does not occur running with default access permissions, it is likely that the custom access permissions are restricting your client from accessing the DCOM Server. Choose custom access permissions and select the Edit button. Grant the client user access permissions.

1. Run DCOM Config.

2. Select the DCOM Server application from the list of available applications.

3. Select the Properties button, or double-click the DCOM Server application in the list.

4. Test the server with "Default Access Permissions," "Default Launch Permissions," and "Custom Configuration Permissions."

   If run-time error '70' still occurs, it is likely that the default access permissions are restricting your user. If this is the case, modify the Default Access Permissions from the Default Security tab in DCOM Config. If run-time error '70' does not occur, it is likely that the custom access permissions are restricting your client from accessing the DCOM Server. Choose to use Custom access permissions and choose the Edit button. Grant the client user account access permissions, or grant a group the client user belongs to access permissions.

There are several group accounts you will find when you configure users and groups on Windows NT. The following list is a summary of who belongs to each group:

Group                     Description

Interactive               Includes all users who log onto a Windows NT
                          system locally (at the console). It does not
                          include users who connect to NT resources across
                          a network or are started as a server.

Network                   Includes all users who connect to Windows NT
                          resources across a network. It does not include
                          those who connect through an interactive logon.

Creator/Owner             The Creator/Owner group is created for each
                          sharable resource in the Windows NT system. Its
                          membership is the set of users who either create
                          a resource (such as a file) and who take
                          ownership of them.

Everyone                  All users who access the system, whether locally,
                          remotely, or across the network.

System                    The local operating system.

Attempting to Access DCOM Server Across Non-Trusted Domains

If your DCOM Server resides in one NT domain, and your client logs on to a second NT domain that is not "trusted" by the first, you will receive run- time error '70' when attempting to access the DCOM Server.

For additional information, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q158508
   TITLE     : FAQ: COM Security Frequently Asked Questions

REFERENCES

For additional information, please see the following article in the Microsoft Knowledge Base:

   ARTICLE-ID: Q176799
   TITLE     : INFO: Using DCOM Config (DCOMCNFG.EXE) on Windows NT

Keywords          : vb5all vb5howto
Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbhowto