In order for a Process to be able to interact with Internet Explorer, you will need to modify some of its settings. By default, Internet Explorer comes with security settings enabled that do not allow an external application to control it.
To change this,  perform the following steps:

1. Open the Internet Options dialog in Internet Explorer and click on the "Security" tab:
 


2. Select the "Internet" zone and UNCHECK the "Enable Protected Mode" checkbox:



 
3. Select the "Local intranet" zone and UNCHECK the "Enable Protected Mode" checkbox:

 
4. Select the "Trusted Sites" zone and UNCHECK the "Enable Protected Mode" checkbox:

Finally click the OK button and restart Internet Explorer. You will now be able to control Internet Explorer for automating all kinds of web sites and web applications.