I am working on development server and i stopped and started Claims to Windows Token Service
Suddenly Central Administration site was down and the website was completely disappeared from my IIS.
if you are in same problem just execute the below command using stsadm tool
stsadm -o provisionservice -action start -servicetype
Microsoft.SharePoint.Administration.SPWebService -servicename WSS_Administration
restart the IIS ...that it you are done. now you can see your website in IIS.