From a newsgroup post: "Based on my research, this issue may appear if you have enabled the Open File Support (OFS) within Tivoli Storage Manager (TSM) Client Version 5.2 or some other third party software (including anti-virus software). Therefore, I would like to suggest that you perform a clean boot or the SBS server and see if the issue persists. To perform a clean boot, follow the steps below:
1. Click Start, click Run, type "msconfig" (without the quotation marks), and click OK.
2. Select "Selective Startup" and remove the check box for "Load Startup Items".
3. On the "Services" tab, click Enable All.
4. Check "Hide all Microsoft Services", click “Disable All”, and clear "Hide all Microsoft Services".
5. Click the OK button and then Click Yes to restart your computer.
6. Try again.
If the issue still occurs, please install the following three hotfixes:
ME833167,
ME826936, and
ME828481.
If the problem is not solved, please run the following command immediately after VSS fails: vssadmin list writers > c:\vss.txt. This will send the output to vss.txt in the root of the C drive. You can check the file for more details on the problem".