virtualbox.org

I deleted the vdi file by using shift+del in windows xp, NTFS file system.

The virtualbox hard disk is 16G, I run a few tools trying to recover
but could not see the file at all. Is there any tool good enough to
recover such a big file? Or, any suffix of smaller files may suggest
they belong to the vdi file?

Thanks very much

I wish you all the best, but the chances are remote, especially if you've continued to use the system. That why you need DR backups