Latest version of windows updating
Then, I would try to manually upgrade to the next build by mounting the ISO (even better extract the files to a folder) and running Setup.
Assuming the upgrade completed successfully, I would then enable the devices one-by-one and would install proper drivers (I prefer to avoid Windows Update and manually install latest official OEM drivers).
This is how I managed to update my Win10/64 system from Ver. My system has an Intel 17-8700 CPU with 16 GB RAM and a 128GB Samsung SSD boot drive installed on an ASUS P8Z77-M motherboard.
Many of you might have been around yesterday and watched the launch of the new Windows 10 S version of operating system that is going to be available on the new range of Microsoft Surface laptops.
This according to Microsoft may signify that your PC doesnt meet the minimum requirements to download or install the upgrade to Windows 10.
This Optiplex is ~2 years old, the CPU is an i5-7500 running at 3.4 Ghz, and it has 12 Gb of RAM.
Unfortunately impossible to do both at the same time, it is necessary to re-download again: -( (There may be a trick but I haven't tested it!!! That is, disable either in BIOS or in Device Manager all not-necessary devices (audio, LAN, Wi-Fi, TV tuner etc) and disconnect any printer and other USB devices.
You won't need them until Windows upgrade is complete, so why let Windows try replacing the drivers and mess them?
I have not lost any applications already installed, documents or accounts!
I would also disable all not-critical services and startup applications.