InvokeHelper() throws Access is denied exception - c++

Question

Community, I have quite interesting and in the same time heavy problem.
I have VB .NET application + Service + C++ application. C++ application generates some data and makes callbacks using InvokeHelper() method:
InvokeHelper(0x60030000, DISPATCH_METHOD, VT_EMPTY, NULL, parms,
eventType, eventValue);
The first parameter is the dispid of method which should be called. Strange approach, but this is not my code and I can not change this way.
In service I have method marked by dispid attribute to get this callback from C++ application.
<DispId(&H60030000)>
Public Sub ServerEvent(ByVal vEventType As Integer, ByVal vEventValue As Object)
RaiseEvent ControlPanelStateChange(vEventType, vEventValue)
End Sub
This code works correctly if I logged on as admin. But if windows user has not administrator permissions, right after calling InvokeHelper() method the next exception occurs:
First-chance exception at 0x75B7C42D (KernelBase.dll) in application.exe: 0x80070005: Access is denied
Do you have any ideas? I have played with DCOM permissions, but result is the same.
Any help would be fantastic!

Answer 1

The solution of the problem is:
DCOMCNFG, right click on the My Computer and select properties -> COM Securities tab -> Access Permissions -> click Edit Defaults and add Network Service to it and give it Allow local access permission. Do the same for < Machine_name >\Users.
Then -> Launch and Activation Permissions, click Edit Defaults and add Network Service to it and give it Local launch and Local Activation permission. Do the same for < Machine_name >\Users.