Was struggling to find Excel.Application or Word.Application in DCOMCNFG on Windows 2008 R2 - followed the workaround on this post (http://www.sevenforums.com/microsoft-office/56884-microsoft-excel-application-entry-missing-dcomcnfg.html) and it seems to work...
1. go to DCOMCNFG
2. In the left tree structure, right click on My Computer and select Properties
3. Click on COM SECURITY tab
4. Give Permissions to Network Service and Users in the "Access Permissions" and "Launch and Activation Permissions" by clicking the Edit Default buttons.