In addition to the other totally accurate answers, you can also buy machines that don't have enough RAM, then mandate a software suite that is guaranteed to push the entire machine hip deep into swap merely by booting to the desktop. Every application opening then is a trial of Windows swapping bits of other things out, to load a bit of the application, then having to swap back in the two virus scanners and the malware shield to check the application just loaded, then swap back out those things to load the next resource for the application, then the checkers back in, then the program opens a network address so the network firewalls need to swap in... on an SSD this is slow, on a hard drive you can easily end up in the hours to load a program like this.
Scanning through the replies, I'll also add that if you are loading your entire profile from the network, this often becomes much more problematic than the IT people may have initially calculated, because even if you can transfer a gigabyte in 10 seconds, you can't transfer a gigabyte in 10 seconds to thousands of users simultaneously, and logins are highly temporally correlated. It doesn't take much at all to have a cascading network failure as a result, even under perfect conditions, as that 10 second window becomes a 20 second window, which catches ten more people and it turns into a 40 second window, and it explodes quite fast from there as suddenly everyone everywhere is waiting for minutes or hours to load from the same overloaded profile server(s).
From what I've witnessed of this, what you'll get is a number of these answers operating at once.
Scanning through the replies, I'll also add that if you are loading your entire profile from the network, this often becomes much more problematic than the IT people may have initially calculated, because even if you can transfer a gigabyte in 10 seconds, you can't transfer a gigabyte in 10 seconds to thousands of users simultaneously, and logins are highly temporally correlated. It doesn't take much at all to have a cascading network failure as a result, even under perfect conditions, as that 10 second window becomes a 20 second window, which catches ten more people and it turns into a 40 second window, and it explodes quite fast from there as suddenly everyone everywhere is waiting for minutes or hours to load from the same overloaded profile server(s).
From what I've witnessed of this, what you'll get is a number of these answers operating at once.