You can NOT back up/restore Windows using the file backup (tab "Backup") without additional procedures. The file backup method does not include any boot information of a Windows installation! Therefore, please remove the Windows system and program directories from the file backup:
C:\Program Files (x86)
Please also remove these files from the backup (if exist on C:):
This saves space on the target disk and also time during the file backup.
To back up the system itself (i.e. the Windows installation), use Image Backup (Start Screen => Image Backup = DR) to create an image of the drive containing the Windows installation. The user data on other drives or partitions can then be backed up using the "Backup" tab.
More information about Image Backup (DR) can be found in the NovaBACKUP manual and on the NovaStor Support website.