This will launch the prompt, where you can choose to uninstall Hyper-V

You can go to Start > “ Turn Windows features on or off” If you have the feature added/running it doesn’t work very well side by side with other Virtual Machines like VirtualBox. Hyper-V is, essentially, Microsoft’s implementation of running virtual machine in your Windows. If you have one of those settings configured as mentioned, this is the reason why you are only seeing 32-bit guest operating systems available when create a new virtual machine. You either have Hyper-V turned on, or have Intel Virtualization Technology disabled in BIOS. It was showing 64-bit operating systems as one of those options in VirtualBox but you don’t know why there are only 32-bit versions listed below. So we know your machine is on 64-bit and perhaps at some point. You are not restricted in running 32-bit of Windows. This isn’t “normal” and you can fix it to enable VirtualBox to support 64-bit OS. If the host machine is 64-bit and you are using VirtualBox to host and running your virtual machine, don’t be puzzled if your VirtualBox is showing you that it can only support for 32-bit of operating system.

Virtualbox windows 10 64 bits