Hi this is quite late so hopefully you've got it fixed (I've had a few updates that have seemed to stick for a long time then finished after a very long delay with no progress in minutes), what is the specification of the system?
It can just be windows being a PITA and not moving the update bar for ages, it can be that if it's downloading a driver or something there is a delay or the connection is running slow, or it can be hardware issues.