Been so long, can I just apply 4.5.2 to 4.0.0? 
http://www.steinberg.net/en/support/unsupported_products/downloads_c4.html
If you have your dongle plugged in, and receive messages about a process which is preventing the update, and you need to re-run the update, ignore them. They are just trying to tell you that they can’t update the dongle software.