A few weeks ago when I was delivering a Reporting Services training, I noticed that on some of students laptops, sometimes the Initialisation checkmark was grayed out in the Reporting Services Configuration Manager.

You can find it here:

This puzzled me, untill I found the reason.

If you are using the Standard edition of Reporting Services, the initialization pane is grayed out in Reporting Services Configuration Manager. You should still see the checkmark.

This is grayed out because scale out to a web farm is not available in this edition. If the Report Server Windows service is running, it is already initialized.

For more information, please review the information in this link for the full software requirements: http://msdn2.microsoft.com/en-us/library/ms143506.aspx

If you would like to install and Configure Reporting Services to Use a Non-Default Web Site, some usefull information can be found here: http://msdn2.microsoft.com/en-us/library/ms155921.aspx