virtualbox.org

I somehow managed to delete a Win7 guest I was using on a Linux host but have recovered two files. The hard drive it used was dynamically sized with an actual size of 7.81G and a virtual size of 39.89G. The two files I've recovered pretty much match those, and I've renamed the smaller corresponding with the settings in VBox.

However, I have no idea as to what to name the larger 39.89G file so that it actually gets used, or how to make sure it is somehow associated ? As it is the machine begins to boot momentarily and then I get a "Fatal: No bootable medium found! System halted" message. Is it somehow possible to fix this by renaming or something, or is this image done for as I have some app info in there I'd really like to recover ?

I'm afraid your description doesn't make much sense. A dynamic VDI should consist of one file. The two sizes relevant to it are its capacity and its current size (the latter can be any size up to the former), but that is just two ways of describing one file.

If you have two files then they can't both be the VDI. You need to work out what's what.

If you view the .vbox file with a text editor then you should be able to see the media registry which includes the full folder name and filename of any mounted media.

Frankly, I wouldn't get my hopes up: the larger a file is, the less likely it is that undelete will work, and VDIs tend to be very large. You should create a backup regimen for yourself to avoid future disasters.

Even if it doesn't boot you can try mounting the disk in another VM... but like I said, I wouldn't get my hopes up. If the guest filesystem is history then so is the data on the drive.