OPC Server gives 0x80070005 (Access is denied) error to OPC client not running as Administrator

I have developed an OPC DA server which runs as a windows service. When I try to connect to it OPC client it gives me 0x80070005 (Access is denied) error. However if I run the client as administrator it connects properly. This is a problem since I cannot force clients to run in admin mode. What is the solution to this problem? I tried setting DCOM properties using DCOM config but haven't succeeded.

Cause DCOM Error 0x80070005 appears in the OPC Client application when it succeeds in launching an OPC Server or OpcEnum, but fails to receive a reply from either of the applications. This error could be caused under several conditions: On the OPC Server PC, the OPC Client User Account does not have the right Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Default.

On the OPC Client PC, the OPC Server User Account does not have the right Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Limits.

On the OPC Client PC, the DCOM Default Impersonation Level is set to “Anonymous” instead of “Identify”, and the “ANONYMOUS LOGON” Access Control Entry (ACE) does not exist in the OPC Client PC, Access Control List (ACL) permissions in the System-Wide DCOM settings, Access Permissions, Edit Limits.