I have tried to investigate a similar (if much smaller in scale) problem at one job. Our logins were just taking entirely too long. Granted, we had a notoriou

I have tried to investigate a similar (if much smaller in scale) problem at one job. Our logins were just taking entirely too long. Granted, we had a notoriously "it's on your end" unhelpful parent IT department to work with, but I found just trying to understand the list of steps that go in on the background for a single login to finish on Windows to be something of an occult science. Finding the tools to just measure the different times each step takes was almost impossible; I had hints for a few steps there, a suggestion for one step over here, and so on, but nothing complete. Even an empty profile on a relatively new computer, recently wiped computer was painful.