virtualbox.org

I've tried to install VirtualBox 6.1/Ubuntu 20.04.3/21.10/guest additions on Windows 10 at least 25 times and I cant get any kind of reliability. Sometimes it boots, sometimes it doesn't. It also likes to run slow or completely freeze up. Installing the guest additions makes no difference. I have Hyper-V and Virtual Machine Platform disabled and Windows Hypervisor Platform enabled (started with it uninstalled, tried both enabled and disabled). I suspect my IT department has something locked down but I doubt they know it or can offer any assistance. What are my next steps? Sorry if I'm missing some information but I'll get anything else you might need.

Processor Intel(R) Core(TM) i7-10850H CPU @ 2.70GHz 2.71 GHz
Installed RAM 64.0 GB (63.7 GB usable)
Device ID F2402188-DC85-415D-95B2-EC5765E41D5C
Product ID 00329-10331-65117-AA770
System type 64-bit operating system, x64-based processor
Pen and touch No pen or touch input is available for this display

On the contrary, you have Hyper-v enabled, and the poor and inconsistent performance is no doubt a direct result.

00:00:02.587646 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:02.636401 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:02.636464 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

The FAQ below explains how to disable it properly, but you probably need to get IT involved since I doubt you have permissions needed to follow the FAQ.
HMR3Init: Attempting fall back to NEM (Hyper-V is active).

Ah. Thank you. I did not know I couldn't disable it through Windows Features. Do I need to disable Virtual Machine Platform or Windows Hypervisor Platform in some way outside of Windows Features? After struggling with this I decided to try VMware and it installed Windows Hypervisor Platform. I have it disabled in features but that's not good enough? I didn't have any trouble running the command(s) in the FAQ but I still see the offending lines in the log. As you and the FAQ pointed out, IT may have this locked down. I attached the logs but I suspect you've done all you can for me.

Thank you

The FAQ explains what you need to do.