Hi Jiri,
This issue could occur due to corrupt system files or due to issues with the backup files on the old backup drive.
I would suggest you to run the SFC scan and check if it fixes corrupt or missing system file that is causing the issue. Follow the methods:
Method 1:
SFC Scan:
System File Checker is a utility in Microsoft Windows that allows users to scan for and restore corruptions in Windows system files.
Follow the steps:
a. Type “cmd” without quotes on the Start screen.
b. On the left pane, right click on the “Command Prompt” and select “Run as Administrator”.
c. Type ‘sfc /scannow’ without quotes and hit Enter.
Check if it resolve the issue while performing the backup operation. If not, proceed to the next method.
Method 2:
Consider the old backup files obsolete and delete them, or move them away into a temporary folder.
a. Datafile - MediaID.bin
b. Folder - Windowsimagebackup
c. Computer-name (file name)
Run the Windows 7 File Recovery again to backup the files and the image to test the issue.
Please let us know about the results. We will be more than happy to assist you.