Hi,
This is an alternate method if you are uncomfortable with the original solution.
From an administrative command prompt Run: DiskShadow.exe - then
List Writers - and see what files are on a volume that you want to exclude from critical volumes list by looking at the SYSTEM WRITER output. see what files are on the drive letter of the volume you want to exclude.
Install this hotfix if applicable.
980794 System state backup error in Windows Server 2008, in Windows Vista, in Windows 7 and in Windows Server 2008 R2: "Enumeration of the files failed"
http://support.microsoft.com/default.aspx?scid=kb;EN-US;980794
Then using the information from the list writers output - enter the image paths for the offending files to exclude them from the backup. Once you do this the -allctitical switch should work.
1. Click Start , type regedit in the Search programs and files box, and then press ENTER.
If you are prompted for an administrator password, type the password. If you are prompted for confirmation, provide confirmation.
2. Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SystemWriter
Note If this registry subkey does not exist, please create it manually.
3. On the Edit menu, point to New , and then click Multi-String Value .
4. Type ExcludedBinaryPaths , and then press ENTER. Note
5. Right-click ExcludedBinaryPaths , and then click Modify .
6. In the Value data box, type all binary paths that should be excluded from the system state backup operation, and then click OK .
Note The binary paths should be absolute paths. They should not include environment variables (such as %windir%) and should not be enclosed in double or single quoation marks.
7. Exit Registry Editor.