Allow IIS Application Pool to access special COM objects

Owned by René Pape
Last updated: 23 Sept 2014

Some of the components of the DVI solution are DCOM based, and needs special permissions to be found and executed by the DVI Server application running in the Internet Information Services.

You need to change the permissions in the computer to allow the relevant application pool to execute the DVI Server components. The installation Wizard is doing this automatically during installation, but you need to change it manually if you change the application pool as described in the article Custom IIS Application pool.

You must be a machine System Administrator to perform these tasks

Step-by-step guide

  1. Find and open the administrative tool DCOMCNFG.EXE


  2. Double-Click "Computers" in the middle "Name" column to reveal the "My Computer" icon, right-click it and click "Properties"

    (click picture to enlarge)

  3. Click the "COM Security" tab


  4. Click the "Edit Default..." button within the "Access Permissions" frame


  5. Click the "Add..." button


  6. Click the "Locations..." button


  7. Select the top entry with the name of your computer (here, it is "PDS-RP-PAR8") and click the "OK" button

     

  8. Type the object name "IIS APPPOOL\CustomDVIPool". Replace the "CustomDVIPool" part of the name with the actual name you have used when creating the custom application pool, but keep the "IIS APPPOOL\" prefix (be aware that there is a space between IIS and APPPOOL).
     

    The IIS APPPOOL area is not browseable, so you wouldn't find it if you click the "Advanced..." button and use the "Find Users and Groups" dialog, so you must type the full name yourself (or copy and paste it from here)

     

  9. Click the "Check Names" button and ensure that your application pool name now appears underlined. Click "OK" to close the window


  10. You will now find your application pool name in the list of group or user names, and "Local Access" is allowed. Click "OK" to close the window


  11. Click the "Edit Default..." button within the "Launch and Activation Permissions" frame


  12. Repeat steps 5 to 9 to add your application pool name within this window, then check "Local Activation", "Allow" to make your window look like this:


    Then, close all windows one at a time by clicking the "OK" button and finally close the "Component Services" window.