If you encounter VERR_ALREADY_EXISTS error in VirtualBox when creating a VM, installation or uninstalling extension, or anywhere else, just refer the solutions ...

Huzzah. How to install the extension pack for VirtualBox 7.0 To fix this issue, you must first download the extension pack. There is only one file for this and it works for all platforms.

Learn how to fix FATAL, No bootable medium found, System halted error in VirtualBox. It occurs if the ISO file is not attached to the virtual machine.