Pernat1y pegged it. Hyper-V is running. And just in case you ask, "How did this person get into my PC?"
, your screenshots show the telltale green turtle
virtualization icon in the guests' Virtualbox window status bars.
The choice of animal is appropriate: Your guest is running, just really slow. This is because a service that uses Microsoft Hyper-V is running on your host PC. Normally Hyper-V blocks Virtualbox. But your PC is of the type and OS where Virtualbox can attempt to run the guest using the Hyper-V engine. This arrangement is still being developed and isn't 100% yet.
If VirtualBox is running without Hyper-V enabled, and nothing else is interfering with hardware virtualization (VT-x / AMD-V), then the usual virtualization icon (
) will be seen in the Status Bar.
To turn Hyper-V off completely, do this:
1. Shut down all programs. You will have to reboot your host.
2. Look into the 64-bits tutorial, 2nd post, points 2 & 3 and ensure that none of these things are running.
3. Find the Command Prompt icon, right click it and choose Run As Administrator.
4. Enter this command:
bcdedit /set hypervisorlaunchtype off
5. Enter this command:
shutdown -s -t 2
6. When the computer turns off, unplug it for 20 seconds. Then plug it in again and boot up Windows 10.
Your Virtualbox should be running now. If the green turtle still appears and the tell-tale lines are in the log, try all the steps again. If you don't get the standard virtualization icon, post back exactly what you did and we'll try to help some more.
For further info, see
I have a 64bit host, but can't install 64bit guests and
https://www.tenforums.com/tutorials/139 ... puter.html