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Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 13:07
by vish05
i tried everything from disabling the hyper-v to others still getting the blank screen underscore blinker isntead of installing the ubuntu setup on the vm

Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 15:27
by mpack
Hyper-v is enabled.
00:00:08.609493 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:08.664922 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...
See
HMR3Init: Attempting fall back to NEM (Hyper-V is active). To cut to the chase: do the bcdedit thing, following by a reboot from full power down. Fast reset on a laptop is probably not enough.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 15:38
by vish05
i tried that cmd prompt stuff and cold boot also. still it's the same scenario
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 16:01
by vish05
I'm trying all this thing since yesterday and now i'm losing my cool on my setup as i have to do work on HDFS setup.

Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 16:01
by mpack
If you tried it then the problem would be solved. Believe me, I have had this conversation many times, we know that the FAQ is good info.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 9. Mar 2021, 16:03
by vish05
trust me bro i did those cmd stuff still it's showing that turtle in the task bar at guest os
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 01:07
by scottgus1
Do you have anything installed that wants to re-enable Hyper-V? Docker?
If the green turtle is there then Hyper-V has been turned back on by something. Corporate IT policies might force it on. DeviceGuard, CredentialGuard, Windows Defender's Core Isolation might force it on.
The vast majority find the bcdedit and shutdown commands sufficient. But there have been a few who have other things that re-enable it.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 06:21
by vish05
no i don't have docker or else likewise.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 06:23
by vish05
i did the secure boot stuff also still it's not working
now you guys tell me what should i do to get this work

Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 18:20
by scottgus1
Regrettably, the tutorials we posted are all we know on the subject.
The only other thing I would try is to switch in a different hard drive and do a fresh install of your host PC's OS only, then Virtualbox. It should run sans green turtle, or maybe just one run of the tutorial commands.
Then install one of your other programs, reboot, then try Virtualbox again. Rinse and repeat. Once the green turtle shows up, then the offending program has been found.
vish05 wrote:now you guys tell me what should i do to get this work
We have been trying. Know that free Virtualbox users are entitled to zero (0) support, and the forum 'answerers' are all unpaid volunteers. Keep this in mind as you ask
politely for further help. That line you wrote is pushy, which won't go far here.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 20:06
by vish05
obviously that wasn't intended to be harsh , but being the site moderator you guys can reach to the devs to help us out
as after giving three to four hours of try daily for three days to install a single thing then obviously anyone would get frustrated.
btw nothing is ever meant to to be harsh from my side and if it seems like that then yeah it's a sorry from my heart guys.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 20:13
by mpack
Scott is being polite, it's his only weakness. Unless Microsoft wrote a version of Windows especially for you then I (and I believe we) believe that the FAQ is correct, if followed carefully.
As I said above, we have had this exact conversation a thousand times. Every single time the user complains that his case is unique, why won't anyone believe him?? - and then the solution always ends up being something that was (pretty clearly) explained in the FAQ, because the FAQ has been honed for completeness, clarity and accuracy over time.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 10. Mar 2021, 20:54
by multiOS
@vish05
If you are having issues with the CLI method, which can happen if feeling frustrated, or if 'Command' isn't launched with full Admin privileges, you could try the "Hyper-V Switch" app available here:
https://unclassified.software/en/apps/hypervswitch It's a very small (23 KB) portable app (no installation required). A very simple GUI which 'auto-performs' exactly the same bcdedit actions as the CLI method and prompts reboots on completion It can also be used to both activate and deactivate Hyper-V if you need to 'toggle' that feature. You just need remember to "Right Click - Run as admin" to use it.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 11. Mar 2021, 03:33
by BillG
If you can see the hypervisorlaunchtype switch in bcdedit, something is your system is capable of turning it on. Otherwise that entry simply would not be there.
bcdcedit.PNG
There are multiple things which can do this and the list keeps growing. Some are from Microsoft, many are from third party products. If you can't find all of them and remove then, the "silver bullet'" cure is to prevent the hypervisor from loading. But you have to follow the instructions carefully. After you edit the bcd store, the hypervisor is still loaded. It will remain there until you do a shutdown followed by a cold start of your PC. If you do it properly, the hypervisor will not load.
It is possible to have a PC capable of running Hyper-V vms and also have a fully operational VIrtualBox system. This not just theory, I have one (not on this PC, which you see does not even have the switch). The only trick is that you must do a full cold restart after you change the launchtype parameter, so that the hypervisor loads in one situation and does not load in the other.
Re: Black Screen issue while installing ubuntu 20.04 LTS
Posted: 15. Mar 2021, 08:05
by Steve_JJ
I am having the exact same problem i.e. I can't stop Hyper-V being enabled despite following the advice in the Virtual Box FAQ.
I tried following the advice
here and
here.
Hope that helps someone, unfortunately it didn't help me.