Using VMware Server ESXi (freebie version)

I have a Virtual Machine (win 2k3 r2 server).
When I first provisioned it I took a snapshot of it. 
I recently tried to clone the primary drive using my standard hardware-based method to grow a windows disk. (using knoppix, clone drive to a new drive, make it bootable, then I intended to extend the partition via diskpart from within windows).
This process failed; I tried setting the cloned drive (via the vmware gui) to replace the original drive, boot and be done. This didn't work out so well. The machine never booted. I checked the boot order, the disk location and all the basics I usually do.

As a failsafe, I then tried changing all the settings back so the machine would boot to the original drive and I could figure out (as I eventually did) a better way of growing the disk. However when I powered on the machine with the original drive, it reverted back to that initial snapshot I created; It lost all the changes since.

I looked in the file system and found a few files, I think the keyfile here is one named "delta" and I'm assuming that's the disk I want, but I can't find a way to have the Virtual Machine actually use that drive/file. It isn't available to add when I go to add an existing drive.

Do I need to somehow commit that delta to the original drive and then boot from it again? Can you point me in the right direction? 

I've since discovered the proper way of growing drives using "vmkfstools" but I need to get back to the original state of the machine to try this out. Any help would be greatly appreciated.