I turned on Insider Preview Fast on my Win10Pro VM. Windows Update proceeds normally through downtown and seems to pause at installing 32%. After several minutes delay Update fails with error 0x800705b4. I must reboot before Update will try again. This happens with every Insider Preview release i've tried. ~Stan
Hello Cat2Mav, take a look at this article that explains the cause of this issue and a possible solution.
Success. I installed a fresh copy of Win 10 Pro from the latest .iso file. Updating to the Insider Preview completed without a hitch.