Low Maximum execution time
Follow  below steps and change that file.


Go to your XAMPP installation Folder and edit - ..\xampp\php\php.ini file.
Use the FIND function of your editor an look for "max_execution_time"
in that line you will see the value attributed to "max_execution_time"
change it to max_execution_time=120
Save the php.ini file.
Restart the XAMPP Server
Proceed with Drupal Commons installation.