Can't boot my VirtualBox VDI — messed up storage setting

Question

I messed some storage setting up in the VirtualBox GUI, and now I can't boot my VDI. I tried just creating a new VM and using the existing drive. That didn't work either.

I get:

This is what my storage settings look like:

Answer 1

There are two things that I can think of:

1. Your inserted SATA controller (U2.vdi) is wrong and you need to insert the correct one.
2. Your IDE Controller is empty (which is less likely than the first solution).

EDIT: To resolve the first issue you have to follow these steps:

• right click on the U2.vdi and remove it by Remove Attachment.
• click on the Controller: SATA.
• on the right hand side of the selection, click on the Adds hard disk icon.
• select the Choose existing disk option.
• navigate to the address of your .vdi files and choose the right one (U3.vdi maybe?!)
• click on open.

Now check to see if it boots up with current settings. If yes, enjoy! if no then follow these steps as well:

• right click on the empty IDE controller and remove it by Remove Attachment.
• click on the Controller: IDE.
• on the right hand side of the selection, click on the Adds optical drive icon.
• select the Choose disk option.
• select the correct disc and click on ok.