Word COM in scheduled task on Windows Server

I have an application that uses COM to automate Word. It needs to run even when a user is not logged in. I achieved this on Windows 7 by making it run as a scheduled task which runs at startup and doesn't require a user to be logged on. I also had to use the 'hack' where you add a 'Desktop' folder in 'C:/Windows/SysWow64/config/systemprofile'.

I tried this same method in Windows Server 2012, but it doesn't work. I can see in the task scheduler that the application is starting an instance of Word. However, it then appears to 'hang' and nothing happens. I think perhaps the invisible instance of Word is showing an error message which causes the whole thing to hang, as I cannot dismiss the message.

Has anyone else had trouble getting COM to work on windows server? Is there any way of showing hidden instances of Word to see if an error dialog is showing? Or any other way of diagnosing what the problem is?

I know ideally we would have an app that created the word documents without using COM, but this is not an option at the moment.