Microsoft Default Manager sets search defaults on your browser and notifies you when other programs attempt to change these settings. You can also opt in or out of a program which allows Microsoft to collect additional information about your system configuration.
Here are a few things you may want to know about the Microsoft Default Manager:
If you have installed Windows Live Essentials, Microsoft Default Manager will be installed into your Computer. It is a part of the Bing toolbar.
The process is named DefMgr.exe and is located C:\Program Files\Microsoft\Search Enhancement Pack\Installers\Default Manager folder. You can also access it via Start Menu > All Programs.
If you have set Bing as your default search engine, you can set the Microsoft Default Manager to inform you if any change occurs.
If you opt to notify you of changes in defaults, a new dialog box may open asking (depending on your current search engine), whether you want to change to Bing or keep you existing search search engine.
You can also opt to let you prevent any program from suggesting changes to your default search engine.
If you find that it frequently troubles you with a pop-up and/or an icon appearing in the notification area, every time you start Internet Explorer, press the Reset IE button, on the Advanced tab of Internet Options, restart Internet Explorer and see if it helps.
If you wish, you can also uninstall Microsoft Default Manager from the Control Panel, Programs and Features applet, in Windows 7.
How useful is this program!? Not really in my opinion. I would have rather liked to see more options, to set and protect a few more important Windows & IE defaults here, and not just Bing. This is simply speaking a Bing Search Default Protector!