Error "Unable to read data from the Metabase. Ensure that Microsoft Internet Information Services is installed" while installing Exchange 2010 on W2K8

PROBLEM DESCRIPTION:
While installing Exchange 2010 on Windows 2008 R2 some times admins can see two error messages

Errors:
- Unable to read data from the Metabase. Ensure that Microsoft Internet Information Services is installed.
- Unable to access the ‘Default Web Site’ on this computer.

CAUSE: Exchange 2010 Prerequisites are not met successfully

SOLUTION: One can follow Microsoft Article to make sure all prerequisites are met:

http://technet.microsoft.com/en-us/library/bb691354(EXCHG.140).aspx

If all common roles are being installed on one server as I had to do some time back for test environment following is what is needed to be executed from Windows Powershell (should be started with "Run As Administrator")

- 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