virtualbox.org

I enabled Hyper-V on my Surface Pro 4, which prevented my Linux VM from starting up. I disabled Hyper-V, but, I still have problems. When I start the VM I get to a black screen with a cursor in the upper left hand corner, and, it is stuck there. Is it unable to boot from the virtual disk? Was it damaged by Hyper-V? Can it be repaired?

If the VDI was damaged then VirtualBox would tell you, and it wouldn't get as far as it did.

Next, enabling Hyper-v might cause VirtualBox to give you an error message, it would not corrupt anything. I suggest that you look to other causes of corruption, for example how much free disk space do you have?

I wonder if vt-x is disabled now. I have not found any way to query that. I cannot get to the BIOS, if Surface Pro 4 has a BIOS. The UEFI menu does not have an item for virtualization.

Again, VirtualBox would give you an error message if VT-x was required but wasn't available. In order to get the symptoms you describe in anything like that way, you would have had to manually disable VT-x in the VM settings, after installing a 64-bit OS. And the OS itself would probably complain about that as it boots.

Your problem seems like something more basic, like bad graphics drivers in the guest.