Re: Hard Drive Data Unrecognized
First of all, can't help you regarding the gzipped image as, I don't use dd, and have found through experience that making image backups of Windows partitions is best done using Windows tools -- the best of which are available for FREE these days.
Second, if the partition that is supposedly blank is formatted NTFS, is could simply be that the filesystem is corrupted, thus, Linux can't read the partition information.
If that's the case, you might be able to fix that partition using CHKDSK, but you would have to run that from within Windows as there is no Linux equivalent of it.
If you simply want to recover files from that partition, then do NOT run CHKDSK but instead, you need to connect that drive to a PC running Windows, and run a Windows data recovery app. If you're interested in following that approach, read on ...
In my experience, Windows filesystem utilities have been best at recovering data from former Windows partitions; Linux filesystem utilities have been best at recovering data from former Linux partitions. Your best bet at recovering data in a useful form from the Windows filesystem is to do as indicated below ...
Since your data was on a Windows partition, based on my experience at doing this successfully, my suggestions are the following:
[NOTE: If your PC has a working copy of MS Windows on it, skip to step 4]
1) Find someone with a working MS Windows PC
2) Remove your drive from this PC.
3) Connect your old drive to the MS Windows PC.
4) Download and install the trial version of RecoverMyFiles from Runtime Software in MS Windows.
5) Right-click the RecoverMyFiles shortcut and select "Run as Administrator"
6) Select the option to Recover a Drive
7) You will get a list of drive, scroll down to find the one for your USB stick or memory card
8) Select Automatic Driver recovery, press Start button
9) It will run for a while but when done, will show a directory tree in the left pane. Do NOT interrupt it.
10) When done, browse the folders in the directory tree -- and be SURE to check the filesizes of the files you want to recover. If the filesize is zero, the file is trashed and you will NOT be able to recover it.
If the files look OK, you will need to contact Runtime Software to purchase a license for the recovery. You won't have to reinstall the app; instead, they will email you an activation code which you can use to turn on the recovery feature.
According to their website, the "standard" version of the app is $70 USD. They also have a Pro version for $99 dollars, but if you go to the website below, you can compare the features and (at least for me) the extra cost wasn't worth it:
Your data ... your money ... your choice.
Ubuntu 16.04 Mate, Mint 17.3; MS Win 8.1, MS Win10 Pro.
Will not respond to PM requests for support -- use the forums.