I'm also having problems installing this update. As others have mentioned it takes a long time and then takes a long time to roll back.
Again this is the 64 bit version on win 8.1pro - no changes to start menu structure and all the usual things attempted (clearing download cache, running the "fix problems with updates" software.. everything)
I'm only posting in the hope that there will be sufficient activity for microsoft to fix the issue with their update.