Accessing Office Word object model through asp.net results in "failed due to the following error: 80070005 Access is denied."

Ok, I resolved this problem with this steps:

1. In the command line put DCOMCNFG
2. Expand Console Root > Component Service > Computers, right-click on My Computer, And Select Properties
3. In the Tab COM Security > Launch and Activation Permissions Click in Edit Default
4. Add the User (Ex. IIS_IUSRS) or service
5. Check Allow Local Launch and Local Activation

Then Excel, Word and other applications can work, good luck.

This worked for me:

1. In the command line put DCOMCNFG
2. Component Services -> Computers -> My Computer -> DCOM Config
3. Find "Microsoft Word 97 - 2003 Document" (If it is missing check if your Word is also 64 bit (if your Windows is) if it is not run mmc comexp.msc /32 instead of DCOMCNFG on step 1 as suggested by Darkseal here)
4. Right click -> Properties
5. Go To Tab Security and Edit the "Customize" radio buttons so that IIS_IUSRS could have rights for launch and access
6. Go to Tab Identity and choose "The interactive user"
7. Apply changes and try again
8. If all this fails, go also to tab "General" and in "Authentication Level" drop down choose "None".

Look in the Event Viewer, under Windows Logs, System, on the server machine where Word is installed. Do you see an event logged that reads something similar to:

The machine-default permission settings do not grant Local Activation permission for the COM Server application with CLSID {148BEE7F-6123-41EE-8CCA-E390902BD0D8} to the user SomeMachine\SomeUser SID (S-1-5-21-483881670-2168941642-1987552629-1003) from address LocalHost (Using LRPC). This security permission can be modified using the Component Services administrative tool.

If so, run DCOMCNFG.EXE, and go to Component Services, Computers, My Computer (or whatever name), DCOM Config (and you can just answer "No" if it asks if you want to fix anything) and if the event log message is for an application, then find it by the name in the event log message, here by item name, and if the event log message is for a CLSID (like the example above) then find it by the CLSID "{148B...}" (that's just a random CLSID I pasted in -- probably it will match your 000209FF... above), and select More actions... Properties, to the Security tab.

Here, you can select [x] Customize and then Edit, to add permission for the appropriate user account to activate and access the required DCOM application or class.

It's just a guess, but give that a try, or something along these lines (i.e. granting access to the CLSID via DCOMCNFG).