If you are facing problem to install .NET Framework 3.0 with 2.0 by CONTROL PANEL TURN ON or OFF WINDOWS FEATURES option. Then follow the procedure step by step
STEP 1: First press WIN key and you will see your START PAGE.
STEP 2: Then type COMMAND PROMPT.
STEP 3: Right click on it and below the page you will find a option to run this as ADMINISTRATOR.