FIX: "Access to the Registry Key Denied" Error Message When You Register .NET Assembly for COM Interop


When you try to register a .NET assembly for COM Interop, you receive the following error message:
COM Interop registration failed. Access to the registry key denied
NOTE: The error message may contain the key name in some instances.

This error can occur under the following circumstances:
  • You build an assembly that registers itself for COM Interop. -or-

  • You use the Assembly Registration utility (Regasm.exe) to register the assembly for COM Interop.
The error may occur even if the person who performs the operation is an Administrator on the system.


This problem occurs because the current user does not have the correct permissions for the following key in the Windows registry:
HKEY_CLASSES_ROOT\Component Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}


Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, click the following article number to view the article in the Microsoft Knowledge Base:
322756 How to back up and restore the registry in Windows

To resolve this problem, follow these steps:
  1. Log on to the computer with an account that is a member of the Administrators group on the local computer.
  2. Click Start, click Run, and then type regedt32 to start Registry Editor.

    NOTE: On a computer that is running Windows NT 4.0 or Windows 2000, you must run Regedt32.exe to review and to set permissions in the Windows registry. On a computer that is running Windows XP, you can run either Regedt32.exe or Regedit.exe.
  3. Locate and then click the following subkey:
    HKEY_CLASSES_ROOT\Component Categories\{62C8FE65-4EBB-45e7-B440-6E39B2CDBF29}
  4. If your computer is running Windows NT 4.0 or Windows 2000, click Permissions on the Security menu.

    If your computer is running Windows XP, right-click the key, and then click Permissions.
  5. Click Advanced.
  6. Click to select the Inherit Permission from Parent Object check box, and then click Apply.
  7. Verify that all of the users or the groups who will be registering or using .NET assemblies through COM Interop have the following advanced permissions:

    • Query Value
    • Enumerate Subkeys
    • Notify
    • Read Control

    To verify the permissions, double-click the user or the group. If any of the users or the groups do not have any of these permissions, click to select the Allow check box for the missing permissions.

    To add additional users or groups to the list, click Add in the Advanced Settings dialog box. Typically, as long as the Users, the Power Users, and the Administrators in the group are present with the correct permissions, everything works correctly.
  8. Close Registry Editor.
  9. Register the .NET assembly for COM Interop by using Microsoft Visual Studio .NET or the Regasm.exe utility.
This bug was corrected in .NET Framework 1.1.

Article ID: 327507 - Last Review: Apr 28, 2008 - Revision: 1