Install / update with authenticated proxy ?

We have 4 SOLIDWORKS 2016 Premium seats. Trying to run/modify/update via Installation Manager we receive a warning that Installation Manager cannot contact the SOLIDWORKS server to determine which products we are entitled to install:

I am trying to run the Installation Manager from behind a (recently installed) authenticated proxy. In almost all cases our applications pickup the authentication settings from Windows but does anyone know if this should be the case with SOLIDWORKS Installation Manager or if there's a location where I need to manually enter the proxy authentication details? Failing somewhere to enter the proxy authentication details does anyone know or know where I might find the domains used by Installation Manager so I can have these setup as unauthenticated on our proxy? Any help would be greatly appreciated!

SolidworksAdministration