I'm on build 9860 right now. When I try and install the new releases through the built in mechanism, I get one of two Windows Update errors: 0x8007003 and 0x80240016. I've tried using the fixit tools, reg cleaners, etc. to no avail. I download the 9879 update from here: http://windows.microsoft.com/en-us/windows/preview-iso-update?os=win10. Should I just put it on a flash drive and boot from it and do an in-place upgrade? Any other suggestions?
So I have the ISO mounted and ready to install. I'm at the screen where it says I'm going to "Install Windows Technical Preview" and "Keep Windows settings, personal files and apps". Does this mean I'm only keeping Store apps, or will it do a traditional upgrade where I lose nothing?
Right, that is how I did the original build but now I'm talking about going Windows 10 Build A -> Windows 10 Build B.
Don't use "Windows Update" from the Control Panel. Instead, use charms, PC Settings, update and Recovery.
Not using Windows Update. I was using the "Preview Builds" functionality. It doesn't work though, I get the errors mentioned in the OP. I'm trying upgrading from the ISO now.