When importing an OVF (Open Virtualization Format) file into VirtualBox, you might need to change the storage controller to ensure it's compatible with VirtualBox. This guide provides a step-by-step process to change the storage controller.

Step 1: Open VM Settings

1. Start VirtualBox.

2. Right-click on the virtual machine in the list and select Settings.
   

Step 2: Remove Existing Storage Controller

1. In the Settings window, click on Storage in the left menu.

2. In the Storage Devices section, select the existing controller.

3. Click the Remove button (minus icon) to delete the existing storage controller.

Step 3: Add a New Storage Controller

1. Click on the Add Controller button (plus icon next to Controller).

2. From the drop-down menu, select the type of controller you want to add, such as IDE or SATA.

Step 4: Attach Disk to New Controller

1. With the new controller selected, click on the Add Hard Disk icon (plus icon next to Hard Disk).

2. In the Choose Disk window, select the disk with the VDI extension or your preferred disk format.

3. Click the Choose button.

Step 5: Verify and Start the VM

1. Confirm that the new storage controller and disk are correctly listed in the Storage section.

2. Click OK to save the settings.

3. Start the virtual machine to verify that everything is working correctly.