Hello!
Here's the steps, it took me a while to figre it out
- Start the router with the reset button pressed, until it flashes green-red
- Install Virtualbox, restart your pc to install bridge adapter, and then install a copy of Windows XP 32 Bit
- Into windows XP install "Microsoft Loopback Device", that's because DG384 tool it's bugged and will not allow you to select the correct adapter until it senses another another LAN adapter
- Connect the router directly to your PC using port 1
- Select the correct adapter this time, the one which is connected to your router
- Check that into the Netgear DG384 folder there is the OEM firmware you want to upload, it must be in the same directory of the executable
- The software should allow you to select your router device and start the firmware upload, it will take about 15 minutes
- It will start a check, and will fail at 95%, don't worry, poweroff the router and power it on again, now you have the OEM firmware again and you can flash the old 21.02.03 that will work