Was the plugin installed by someone who has Administrator rights to the machine?
Does he has is firewall enable? Could be blocking port 4747 that the plugin uses.
In IE does he have "Enable third-part browser extensions" enable?
He is using the 32 bit IE? Separate installer for 64 bit IE and Windows 8.
Yes the plugin was installed by someone with Admin Rights
Im not sure about the firewall wouldnt that be standard for all users though?
Where would I check for this setting "Enable third-part browser extensions" ? under security settings?
I have Compared his security settings to a user whose IE is working and everything seems to be the same.
Please verify that the cookies are working as expect on that machine (described for IE11 below).
Open the F12 Developer Tools
Click on the Network button
Enable capture of network traffic by clicking the green triangular button in top toolbar
Capture some network traffic by interacting with the page
Click on DETAILS/Cookies
You should see the key "PluginEnabled" having the value "true"