installed the Exchange2010 pre-requisites for Windows 2008 R2:

 
Open Powershell with elevated rights using "Run As Administrator", and run below cmdlets to install prerequisites...
 
  • Import-Module ServerManager
  • Add-WindowsFeature NET-Framework,RSAT-ADDS,Web-Server,Web-Basic-Auth,Web-Windows-Auth,Web-Metabase,Web-Net-Ext,Web-Lgcy-Mgmt-Console,WAS-Process-Model,RSAT-Web-Server,Web-ISAPI-Ext,Web-Digest-Auth,Web-Dyn-Compression,NET-HTTP-Activation,RPC-Over-HTTP-Proxy -Restart
  • Set-Service NetTcpPortSharing -StartupType Automatic
 
Exchange 2010 Prerequisites