Currenly i have two calenders in my outlook. One is Exchange calender and other one is my personal folder calender.
I have applied the following settings
Under Accounts Setting ---> Email Setting -----> Change Folder
Then I select mail delivery locationa as my Personal folder. Bebause of this setting my default calender changed to Personal folder.
But I need to change defalut calender back Exchange calander without chaning the defalut mail delivery location.