I am running Windows 10 (build 16299) on a Dell XPS 15 9550. When I enable the Intel virtualization technology and install Hyper-V the laptop blue screens on startup every time. The only way to recover it is to disable the Intel VT in the BIOS. I can then start the machine but can't use Hyper-V as it needs the Intel VT. I can then uninstall Hyper-V and re-enable Intel VT and everything is still fine. What I can't do is use both, which I need to do.
Are you running any third-party anti-virus? Apparently some AV solutions these days add themselves as a hypervisor in order to gain even lower-level access to the system, in which case trying to start Hyper-V would definitely cause problems because a system can only have one hypervisor running at a time. Disabling VT allows you to recover because Hyper-V won't start if VT is disabled, but not all hypervisors require VT to be enabled.
Thanks for the quick response.
Unfortunately I actually need to use Docker which currently only works with Hyper-V on Windows. I have had VMWare and VirtualBox working in the past, but neither are supported by Docker right now.
I have seen some posts suggesting Sophos virus checker could be a problem, but I use McAfee. It did make me wonder about that though. I didn't know they installed themselves as virtual machines as you describe. Even if they do, it shouldn't really cause a blue screen. Of course, I cannot work without a virus checker, but I will uninstall it over the weekend and test it. If it is proven, I will raise it with McAfee and maybe choose a different checker.
I'll post back what I discover.
For what it's worth, ever since Windows 8.1 I've just stuck to Windows Defender. Third-party AV in my opinion for a while now has become more trouble than it's worth. They're typically some combination of bloated, expensive, "noisy" with respect to notifications, and obstructive of your own legitimate activity. They also hook the OS in ways that Microsoft does not recommend and does not support, which means they won't guarantee that the mechanisms those AV solutions are using will continue to be available, and in this era of major Windows 10 releases arriving every 6 months, the chances of AV causing a problem during an upgrade are relatively high. In fact even for regular monthly updates, there are countless cases of BSODs after updates are installed that turned out to be caused by AV breaking after Microsoft changed something that AV wasn't supposed to be using in the first place. Most recently that happened with the Meltdown patches. Again, some AV solutions caused systems to be unbootable after the Meltdown patch was installed, to the point that Microsoft now has a policy saying that if you have third-party AV solutions, they must set values in the registry confirming that they will NOT break if updates are delivered, otherwise Microsoft will stop delivering Windows updates to that system. The idea that AV has to keep saying, "Yes, I won't break anything" in order for your PC to keep getting updates seems completely backwards to me, but that's where we've ended up. Microsoft is tired of taking the heat from users claiming that a Windows update bricked their PC when in fact it was the AV solution -- but the user wouldn't know that because from their perspective, their PC worked before the update and doesn't work after the update. And some people actually pay for AV solutions to gain this privilege....
Anyway, that's my soapbox. Good luck with your troubleshooting.
I second this opinion -- and also note that the only real way to get rid of a package like McAfee, Norton, etc. is with a clean install of the OS -- even if you run the uninstaller, components will remain - and these components can still cause problems.