I have a 2012 R2 server (VM in Hyper -V).
It rebooted after applying updates and keeps hanging at "Updating your system (7%)" (sometimes 6%)
The server was fully up to date a month or so ago, so it's a recent update that is messing it up..
Here is what I have tried so far:
1. removed Nic in Hyper-V
2. Increased RAM / CPU
3. Rebooted in to Safe mode
4. Rebooted in to Last Known Good Config
5. Rebooted in to Debugging Mode
All just go right back to Updating system and then Hang.