One of my customers runs a SBS 2011 server with Exchange 2010. I consider it a very clean server. Suddenly, after three years, I had issues with the Windows Server Backup.

Opening the WSB console, I would get the message Reading Data, please wait….

I knew that the first thing I should check was the VSS writers. When I tried to run vssadmin list writers from an admin level command prompt,  I would get the message: Waiting for responses. These may be delayed if a shadow copy is being prepared.

Rebooting the server didn’t help.

I tried the wbadmin delete catalog command, but that didn’t help.

I then found this blog post from ServerFault.com which provided instructions for stopping specific services, reregistering VSS related DLL’s, and then restarting service. Eventually this solution worked for me!

Here’s a look at each of the looking at each of these three parts of the solution:

Step 1 – Stop specific services

You can run these commands one at a time from a command line prompt, or put them into a  batch file and run them:

net stop “System Event Notification Service”
net stop “Background Intelligent Transfer Service”
net stop “COM+ Event System”
net stop “Microsoft Software Shadow Copy Provider”
net stop “Volume Shadow Copy”
net stop VSS
net stop SWPRV

Note #1: Stopping the COM+ Event System will also cause several other dependent services to be stopped. Take a note of these dependent services so you can make sure they are restarted later on

Note #2: When I ran these commands, the COM+ Event System service did not successfully stop — it will have a status of  “Stopping…”. But it needs to be successfully stopped for the rest of the solution to work. If this happens to you, here’s how to stop it:

• Open up another command prompt window
• Type: sc queryex eventsystem and press Enter
• Note the associated PID# for this service. Let’s say the PID# is 408
• Next type:  taskkill /pid 408 /F  and press enter’’

Step 2 – Reregister DLLs

Now copy the following commands into a batch file and run it from the command line

regsvr32 /s ATL.DLL
regsvr32 /s comsvcs.DLL
regsvr32 /s credui.DLL
regsvr32 /s CRYPTNET.DLL
regsvr32 /s CRYPTUI.DLL
regsvr32 /s dhcpqec.DLL
regsvr32 /s dssenh.DLL
regsvr32 /s eapqec.DLL
regsvr32 /s esscli.DLL
regsvr32 /s FastProx.DLL
regsvr32 /s FirewallAPI.DLL
regsvr32 /s kmsvc.DLL
regsvr32 /s lsmproxy.DLL
regsvr32 /s MSCTF.DLL
regsvr32 /s msi.DLL
regsvr32 /s msxml3.DLL
regsvr32 /s ncprov.DLL
regsvr32 /s ole32.DLL
regsvr32 /s OLEACC.DLL
regsvr32 /s OLEAUT32.DLL
regsvr32 /s PROPSYS.DLL
regsvr32 /s QAgent.DLL
regsvr32 /s qagentrt.DLL
regsvr32 /s QUtil.DLL
regsvr32 /s raschap.DLL
regsvr32 /s RASQEC.DLL
regsvr32 /s rastls.DLL
regsvr32 /s repdrvfs.DLL
regsvr32 /s RPCRT4.DLL
regsvr32 /s rsaenh.DLL
regsvr32 /s SHELL32.DLL
regsvr32 /s shsvcs.DLL
regsvr32 /s /i swprv.DLL
regsvr32 /s tschannel.DLL
regsvr32 /s USERENV.DLL
regsvr32 /s vss_ps.DLL
regsvr32 /s wbemcons.DLL
regsvr32 /s wbemcore.DLL
regsvr32 /s wbemess.DLL
regsvr32 /s wbemsvc.DLL
regsvr32 /s WINHTTP.DLL
regsvr32 /s WINTRUST.DLL
regsvr32 /s wmiprvsd.DLL
regsvr32 /s wmisvc.DLL
regsvr32 /s wmiutils.DLL
regsvr32 /s wuaueng.DLL

Step 3 – Scan these DLL’s

Next, we will check the integrity of the following three DLLs

sfc /SCANFILE=%windir%\system32\catsrv.DLL
sfc /SCANFILE=%windir%\system32\catsrvut.DLL
sfc /SCANFILE=%windir%\system32\CLBCatQ.DLL

Step 4 – Restart Services

Finally, let’s restart the services we stopped

net start “COM+ Event System”
net start “System Event Notification Service”
net start “Background Intelligent Transfer Service”
net start “Microsoft Software Shadow Copy Provider”
net start “Volume Shadow Copy”

Step 5 – Rerun VSSADMIN

Go ahead and try to rerun the vssadmin list writers command and see if it works.