Running the vssadmin utility and using the “vssadmin list writers empty” parameters returns nothing. The syntax “vssadmin list writers”.
Usually this issue can be resolved by registering the dlls that are needed by the VSS service.
1. From command prompt:
Cd windows\system32
Net stop vss
Net stop swprv
regsvr32 ole32.dll
regsvr32 vss_ps.dll
Vssvc /Register
regsvr32 /i swprv.dll
regsvr32 /i eventcls.dll
regsvr32 es.dll
regsvr32 stdprov.dll
regsvr32 vssui.dll
regsvr32 msxml.dll
regsvr32 msxml3.dll
regsvr32 msxml4.dll
2. After completing the registration of the DLL’s open an command prompt and type: vssadmin list writers
3. You should see the writers listed.
Source http://blogs.technet.com/b/sdoakes/archive/2006/02/03/418722.aspx