I've been using DDU, too. I forgot all about having it, until you mentioned it. I'm wondering if it's a Windows 10 issue or something else, now. I did a clean install yesterday around 6:00 P.M. or so of Windows 10 and the start menu is ok so far with the 375.63 drivers.
It will be a few days before I'm done setting it up to try and narrow the culprit dow.
I do Windows, Windows Update, Drivers, Ninite (Browser/Flash/Air/Everything/Sumatra PDF/Steam). Then I go after Uplay, then Origin followed by Steams games.
Then I usually install everything else. I don't open any of that stuff, except WMP 12, Music, Movies & TV and then all of Cyberlink Media Suite 12 Ultra. I do the Photos app last, as it's been buggy, since 10 was in beta. One day it adds everything and it's icon stops spinning. Then the next 4 times you open it it spins2-8 hours.
I use Unchecky, so no unwanted crap gets on my pc.