HOW TO prevent 3rd-party browser extensions from being installed in IE

There can be some sneaky programs that install not just what they explicitly claim to do but also things like toolbars & add-ons within IE. As most people agree to a software publisher's Terms & Conditions without reading them, they may have deviously add a line that says one of your kidney & your PC are their property.

These add-ons known as browser helper objects may contain flaws such as buffer overruns which impact Internet Explorer's performance or stability.

If you wanted to play safe & prevent any 3rd-party browser extensions from being installed at all in IE8, there is a setting, I came across on IEBlog, that you can use.

Open GPEdit.msc (Local Group Policy Editor) using the Run option in XP or the Search bar in the Start menu. Open Administrative Templates > Windows Components > Internet Explorer > Internet Control Panel > Advanced Page, and set the policy "Allow 3rd-party browser extensions" to DISABLED.

Under the Internet Explorer category referred above, there are a whole lot of other settings that you can also configure. For instance, there is a setting there to "Turn on menu by default". Before you change the setting, you can also read a detailed explanation about that setting.

Also see:
HOW TO disable automatic META tag refresh/redirect through your browser