We recently ran into an issue where the CRM 2011 help menu would display the error Internet Explorer cannot display the page, once we configured IFD.
This is a known issue by Microsoft and they will be releasing a fix in an upcoming rollup.
The workaround below is what we used to resolve the issue:
* please perform the database backup and perform the steps below:
select helpserverurl from configsettings
Set helpserverurl = ”