The Event Log shows: "Volume Shadow Copy Service error: An internal inconsistency was detected in trying to contact shadow copy service writers."

I noticed that if, at a command prompt, I ran "vssadmin list writers", I got nothing back. I was under the impression that all the VSS-compatible writers should be listed, such as SQL Server.

This was KILLING ME all morning. I'd been running backups just fine on this server for the longest time, and it stopped working. I think it was related to my uninstallation of Windows Desktop Search 4.0, but the KB article related to that didn't help. Maybe it was some update? Other articles and forum posts suggesting that I stop the VSS and SWPRV services and register a bunch of DLLs didn't help either.

Finally I found the solution. Well, it worked for me anyway. It was a variation of a forum post I found in google's cache. Here's what I did:

1. Remove the registry key "HKLM\Software\Microsoft\EventSystem\{26c409cc-ae86-11d1-b616-00805fc79216}". You should probably export it first so you can restore it if this doesn't work for you.
2. Reboot.
3. The key is re-created.
4. "vssadmin list writers" returns several writers.
5. The Backup Utility no longer hangs on "Preparing to backup using shadow copy..." longer than maybe 20 seconds. The backup runs normally now!

This server is a VMWare virtual machine, in case that matters.