Let me join this conversation and share my experiences. First of all thank you all for bringing my attention to this feature, and thank Felipe for your deatiled instruction on how to setup Windows Server booting from RAMdisk. I have a single PC configuration, installed Server 2019 in core mode with AO 3.00 and now I started to use Fidelizer pro as well. My way how it is finally able to boot into memory is the following:
I used Felipe's WinNTSetup, firadisk_drivers, firadisk registry hack, and grldr version, and pavgeris' RMPrepUSB Utility utility to format my 64GB pendrive to exFAT file system, install the grub4dos (I copied Felipe's grldr to the directory so this way it copies this to the pendrive), and now it's able to boot into RAM.
My problem however is that 9 of 10 occasion the copying process to RAM is extremely slow. It counts like 10k .. 20k .. 30k so around a few ten kilobytes /second into the RAM, so my 12GB VHD (I also copied some favourite test music into the VHD) takes about 15 minutes to boot into RAMdisk. Which is very long and quite unacceptable.
Do you guys encountered this slow boot issue? Is there a newer or another version of firadisk driver that might help? My pendrive is a Transcend Jetflash USB 3.0 pendrive which is really fast otherwise, it can copy normal files very fast around 120.000 kByte/s in total commander, so it's not my pendrive. Maybe the exFAT format, not sure...