Today I had a ConfigMgr 2007 server where the ConfigMgr backup was failing.

When I looked in the smsbkup.log log file I could see that the backup was complaining "Error: SMS Writer  not found"

I checked the registered VSS writers by runining the following command:

VSSAdmin list writers

No "SMS Writer" showed up in the list.

It turned out that the fix to the problem was to add the "sysadmin" rights to the ConfigMgr computer account defined on the SQL server.

After adding this right to the computer account the "SMS Writer" was added to the list of VSS writers and the backup worked as it should.

Thanks, thats all for now.