I got an error Task image is corrupt or has been tampered with 0x80041321 when saving a Windows Backup task on Windows 7.
This happened after a revert to Windows 7 after it got updated to Windows 10. Solution that worked for me, may not work for you though was:
1. Backup everything and delete all files inside C:\Windows\System32\Tasks\Microsoft\Windows\WindowsBackup.
2. Go to registry and export the keys inside to back it up HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Schedule\TaskCache\Tree\Microsoft\Windows\WindowsBackup then delete all keys such as:
- Windows Backup Monitor
3. Then create your Windows Backup again.