Installing Vault Server encountered this error.
Error 29001. Vault Management error: Could not load file or assembly ‘Microsoft.Web.Administration, Version 7.0.0.0, Culture=neutral,PublicKeyToken=31bf3856ad364e35' or one of its dependencies. The system cannot find the file specified.
This was resolved by checking the components installed for IIS. Specifically, ensuring that the "IIS Management Console" option was ticked. A reboot of the machine is then required.