Microsoft Outlook is the email client that comes standard in the Microsoft Office bundle for Windows operating systems. Windows typically sets Outlook as the dominant program for use in all email-related tasks. If you want to disable the preference for using Outlook, choose an alternative option by changing the options both for your computer and your Web browsers.
Go to the "Settings" option under the "Start" menu, and open the "Control Panel." Click on "Internet Options."
Locate the drop-down menu next to the "Email" title. It should default to "Microsoft Office Outlook."
Click on the drop-down menu and scroll through it until you find the program you prefer to use. Select that program.
Open your Web browser, and go to the "Options" or "Internet Options" menu. This is often located under "Tools."
Select "Programs," then "Internet Programs." Choose "Set Your Default Programs." Your browser's exact menu names may differ, but continue until you locate the mail settings. Change the email setting to the program you want to use.
If you want to remove Outlook permanently, you can do so through the Office Setup program.
If you use more than one browser, make sure you change the settings in all of them.