Overview
A System State backup fails to back up successfully and presents the following error message:
WBAdmin process failed with exit code -4, arguments: start systemstatebackup -backupTarget:<X:> -quiet
This error will most likely occur each time you try to run the backup.
Resolution
The cause of this problem stems from the presence of non-NTFS volumes included in the System State source. If files that need to be included in the System State are present on non-NTFS volumes, they cannot be shadow copied and cannot be backed up. To fix this issue, the non-NTFS partition must be identified and converted to NTFS in order for Windows Server Backup to proceed with the backup generation process.
To identify which volume is the non-NTFS one, do the following:
Open the Disk Management Utility by pressing the Windows+R keys or "Start" and then "Run" to open the Run dialog.
Type diskmgmt.msc and hit the "Enter" key.
Once the Disk Management window opens, locate the drive without a file system label of NTFS.
To convert the non-NTFS volume to NTFS, use the following command:
convert x: /fs:ntfs
...where x: is the volume you want to convert. Please note that although the process is nondestructive, working with hard drive formatting always contains some risk of data loss. Make sure you have a backup of data stored on the non-NTFS partition prior to converting the drive.