Whenever Microsoft Outlook 2010 starts up, it takes you to the Inbox folder by default. You can easily change this setting and can let Outlook launch Calendar, Tasks, or whatever you want.
Click the File (Office) button and choose Options.
The Outlook Options dialogue box will be displayed, here navigate to the Advanced option.
Now locate the Outlook start and exit option in the right side main window and then hit the Browse button located next to the Start Outlook in this folder option.
Here choose the default folder for your Outlook Startup.
Click OK and you are done with the configuration. Now the user-defined folder will start up every time Outlook 2010 is started.