Really can't upgrade to 1607

OK just got the upgrade automatically done this morning on my work VM machine (Win10 x64 pro). This machine has been running flawlessly since the first version of Win10 it had. Every update went smooth, except for this one.

Tried Windows update method, installer get stuck at 32% after 1 reboot, CPU gets to 100% (can see it with vSphere) and nothing else happen, the circling balls are also frozen.

Did a disk clean-up of almost everything except the install files, 45GB Free. Decided to download the iso and launch the upgrade. Same thing, after first reboot, freezes at 32%.

We have multiple similar machines at work and I'm the one who can help the others, we are a small company. Any idea on what could happen ?

Oh this last time I have an error message !

0xC1900101 - 0x30018
The installation failed in the FIRST_BOOT phase with an error during SYSPREP operation

This worked for someone else -

Launch command prompt with administrator privileges.
Press Windows key + X
Click Command Prompt (Admin)
Type the following command:
rundll32.exe pnpclean.dll,RunDLL_PnpClean /DRIVERS /MAXCLEAN
Hit Enter on your keyboard
Exit command prompt
Restart

• Disable (preferrably uninstall) your Antivirus utility before attempting the upgrade.
• Disable General USB Devices (example - Smart Card Reader).
• Do a clean boot and try again.
• If you are upgrading using the .ISO file, disconnect from the Internet during setup, if you are connected by LAN (Ethernet) or Wi-Fi, disable both and attempt setup again.
• If you are updating through Windows Update, when the download reaches 100% disconnect from the Internet LAN (Ethernet) or Wi-Fi and proceed with the installation.
• If that does not work, try using the .ISO file to upgrade if possible.
• If you are connected to a domain, switch to a local account
• If you have any external devices attached to the machine, disconnect them (example, USB keys, external hard disk, printers, non-essential devices).
  
  Microsoft Community

Found the culprit. The Ethernet adapter of the ESXI (Intel E1000) causes windows 1607 to freezes. I changed the adapter to E1000E and everything is fine.

I had the same problem, with my old system. (Asus M3N-HT-Deluxe/Mempipe with EVGA GTX570SC)
Removed AntiVirus, no luck; Ran SFC, no luck; reverted to Windows Defaults, no luck.

I've read much about it, and eventually found that, getting stuck at 32% is almost always a hardware incompatibility.
I eventually found that my old system halted on a DVI connector connected on the Graphics Card. - Very weird!

I did see later on that dual screens have this problem more often. Changing to D-Sub/VGA(blue connector) or HDMI gives the safest results.
I've also seen a Desktop halt on a frontside USB3.0-hub.
And a Laptop halt on an external Graphics adapter.

Hope this helps someone.
Best of luck!