I was working with the SharePoint agent and came across the following error message: SharePoint VSS writer registration failed.
On a Windows Server 2012 R2 VM running SharePoint Server 2013, I found the location of stsadm.exe here: C:Program FilesCommon Filesmicrosoft sharedWeb Server Extensions15BIN
I ran this command which fixed the issue: stsadm.exe -o registerwsswriter