Here's how I have IE 11 set up, I use it to talk to systems running MCD4 SP4, 6.0UR3, and 7.2SP1:
Set Security Level for Trusted Sites and Local Intranet to "Low".
Add all MCD 7+ systems to Trusted Sites list.
Add MCD 4 and MCD 6UR3 systems to Intranet Sites.
Set Compatibility View to display intranet sites in Compatibility View.
Install Root Certificate.
Clear temporary Internet files and re-start IE.