Not able to get the virtual directories in a web site.

I am using below line of code to retrieve all the virtual directories 

Get-WebVirtualDirectory -site 'Default Web Site' -Application "AppName"

but it gives me below error. 

get-webconfiguration : Retrieving the COM class factory for component with CLSID

{688EEEE5-6A7E-422F-B2E1-6AF00DC944A6} failed due to the following error: 80040154 Class not registered (Exception

from HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG)).

At line:1 char:1

+ Get-WebVirtualDirectory -site 'Default Web Site' -Application "ehrms"

+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    + CategoryInfo          : NotSpecified: (:) [Get-WebConfiguration], COMException

    + FullyQualifiedErrorId : System.Runtime.InteropServices.COMException,Microsoft.IIs.PowerShell.Provider.GetConfigu

Can somebody help. i am running this command on windows server 2012

Thanks