Thank you for this thread. In this forum I found the solution for the KB3074683 Update problem:
(probably for user of Nvidia Geforce only)
1. Open the tool regedit and go to this string:
2. Search from here for "ProfileImagePath" in the sub-keys
3. Look for the entry "UpdatusUser" and delete the complete string with "C:\Users\UpdatusUser"
4. Install KB3074683 Update
5. Restart your PC
For me it works!
Tipp: Before you delete the string above export it for your safety!