It is the first thing you need to fix the issue as stated above. For that, you need to run the virtual machine showing the error and go to the Devices > Install Guest ...

VirtualBox is great for testing out a new operating system, but your virtual machines probably aren't that special when you first set them up. Here are a few tips for making them much easier to ...

Before getting started, make sure you have enough space on a hard drive for a Windows XP installation (meaning at least 5 GB) and enough memory to make two systems worthwhile.You can follow most of ...