This error is related to Volume Shadow Copy Service used by NTBackup and has two possible causes:
There are two possible errors 80042306 and 800423f3. The solutions for each are described below.
Possible Solutions for error 80042306
Solution 1 - Apply hotfix Q891957 (Server 2003)
An update is available that fixes various Volume Shadow Copy Service issues in Windows Server 2003: http://support.microsoft.com/default...b;EN-US;891957
You must restart your computer after applying this update.
Solution 2 - Check for corrupt data on the drives being backed up.
Run CHKDSK (Start -> Run -> chkdsk /f) on each drive with the /f switch. Reply yes when asked whether to schedule for next time the machine is restarted. Restart the machine.
Solution 3 - Ensure that VSS does not think this system is still in setup
Perform the steps below to check the status.
WARNING: Using Registry Editor incorrectly can cause serious problems that may require you to reinstall Windows. Use Registry Editor at your own risk.
Open the registry and locate the registry key:
HKEY_LOCAL_MACHINE\SYSTEM\Setup
Ensure both these registry values are set to 0:
If the issue still occurs, reinstall COM+ by following these steps:
Boot to normal mode and in Control Panel, open the Add or Remove Programs tool, and then open the Add/Remove Windows Components tool. Do not make any changes, just click Next. This reinstalls COM+.
Solution for error 800423f3:
Backup did not complete
Volume shadow copy creation: Attempt 3. Error returned while creating the volume shadow copy:0x80042306. Volume shadow copy creation has failed after trying 3 times. The backup cannot continue.
Volume shadow copy creation: Attempt 1. WMI Writer has reported an error 0x800423f3