Hi,
I installed Windows 10 (upgraded to W11) on a NUC with i5-10210u processor, 16GB Ram and 240GB M.2 SSD. After that, I installed Virtualbox with the necessary additional mentioned software. I imported the HASS image in V-Box as described in several YT-tutorials, made the necessary changes in V-Box (processors, network adapters etc) and started the VM. It starts as it should (I assume), as I don’t see any error messages, but when I try to reach the IP-address, followed by 8123 I don’t see the onboarding screen 
. First disappointment achieved. I don’t have a clue where it went wrong. Please help.
It takes a few minutes before the web page will come up after the VM starts. If you’ve waited ten minutes or more before posting this, something is wrong in your networking setup.
I think it’s the network settings then, as the VM is running for a few hours already. Information I didn’t submitted: I used the .VMDK-file for HASS, not the .VDI. I don’t have any clue if that might be the cause? The tutorial video I followed used the VMDK-file.
The NUC uses Windows Defender as “protection” the laptop I tried to access the HASS with uses Bitdefender, just fyi.
Tried some more:
IP-scan finds the NUC, IP-Scan also sees the IP-address the VM uses
I can ping the NUC AND the VM and both answer.
Now only to find what is causing the blockage.
Damn, can’t find the plug that blocks the channel towards my HA-NUC. What information could I share to get some ideas to work on a solution?
Found one probable cause of the problem: I installed TP-Link Deco M4 repeaters and forgot to put them into Acces-Point mode, resulting in my ISP-router giving IP-addresses to network users in another range than the Deco-M4 did, basically having 2 DHCP servers on 1 network. Now DHCP is done by my ISP-router and all users are in the same IP-range.
Unfortunately I still can’t connect to the HA onboarding screen.
Error: Homeassistant.local has refuced the connection
Are you using https:// or http:// to connect to Home assistant?
https:// I tried every other combination. It’s starting to get frustrating 
It should be http://your.ip_address:8123
It’s been a while, but unfortunately the problem is not solved yet. I installed the whole VM again including Home Assistant. When I use “Advanced IP Scanner” on my network both the NUC (Mediacenter) and the Home Assistant are visible and have their own IP-address. When I try to get to the landing page, which in all videos I check about installing Home Assistant on a Virtual Machine (Vitrualbox in my case) is just easy peasy, I still get the message “homeassistant.local” refused the connection.
I can access the Home Assistant Observer. This one tells me:
- Supervisor: Connected
- Supported: Supported
- Healthy: Healthy
Also tried to reach the HA from my phone. Both from the Chrome browser as from the HA-app I can’t reach HA. 