PHP error No input file specified.

I received this error when changing the home virtual directory in IIS 6. The default location was at C:\inetpub\wwwroot and I changed it to E:\. This cause the No input file specified error. To fix it, I open the php.ini file and change the value of the doc_root variable. In my case, I set doc_root = E:\

Restart the server and all the php website work again.