Help please Virtual Machine stopped working

[hayati]

Virtual Machine doesn't open. Is the first time I tried after installing Mavericks and using the Disk Diag app to clean my MacBook Air. It says One or more virtual hard disks, CD/DVD or floppy disk image files are not currently accessible. As a result, you will not be able to operate virtual machines that use these files until they become accessible later.
Press Check to open the Virtual Media Manager window and see which files are inaccessible, or press Ignore to ignore this message.When I check I see VD: error VERR_FILE_NOT_FOUND opening image file '/Users/myusername/VirtualBox VMs/Windows 7/Windows 7.vdi' (VERR_FILE_NOT_FOUND). Details:
Result Code:
NS_ERROR_FAILURE (0x80004005)
Component:
Medium
Interface:
IMedium {05f2bbb6-a3a6-4fb9-9b49-6d0dda7142ac}

I guess this means the file where I had the virtual space is gone? What is the easiest way to make this work? Can I just create a new virtual space? Can I copy the same file from my other computer that is still running? I'm blonde, please don't tell me complicated things I don't want my brain to explode.

[noteirak]

Well the disk seems gone yes. If you don't have a backup and created the Virtual Machine on that computer, better off creating a new one.
If the VM was initially created on your other computer, and you simply moved it accross, then you can try to only copy the file and see if it works, yes.