Step-by-Step guide:

1. Login to MegaUpload.com using your premium account. Click "Transfer Settings" in MegaUpload



2. Choose the "Direct download".(This will activate when you using premium account.)


3. Go to "Options" in your Internet Download Manager (IDM).


4. Choose "Sites Logins" and click "New" to add new premium account.


5. Choose "http://" and type "*megaupload.com". Enter your username and password as well.


6. After that click "OK".

Note:
(*megaupload.com)=* is used in the beginning of the site name because there are redirects to different sub domains on the site.