Server Word automation permissions (some answers and some questions)

Question

I am attempting to use word automation to count the number of pages in a word document. So far i have faced these errors:

1. Retrieving the COM class factory

Answer 1

A solution to avoid having the user logged 24/7 is to impersonate the account and load the user profile programmatically (for this the account needs to a local administrator) before calling Word.

Another solution is to build a windows service that does the same.