MMC Could not create the snap-in when starting Server Manager in Server 2008

Hi,

I have installed windows server 2008 and domain controller is installed and it was working fine. I m facing a problem from few days when try to open server manager and event viewer i m getting error message.The error message is

MMC Could not create the snap-in.  The snap-in might not have been installed correctly.
Name:  Server Manager
CLSID:  FX:  18ea3f92-d6aa-41d9-a205-2023400c8fbb

MMC could not create the snap-in. The snap-in might not have been installed correctly.

Name: Event Viewer
CLSID: FX:{b05566ad-fe9c-4363-be05-7a4cbb7cb510}

please anyone Help to resolve this problem

Regards

Asha