Need Help IE7 Add-Ins

I am having problems with IE 7 freezing several times daily. When I open task manager I see two instances of the same application running. One will be marked "not responding". I think the problem may be with IE 7 add-ins.

When I look at add-ins that run without permission I see many multiples of the same add-in running. Is it safe to delete all but one version of each add-in? Are all these multiples of the same add-in necessary?

Secondly I have "Free Threaded XML DOM Document 3.0" and "6.0" running simultaneously. Do I need both 3.0 and 6.0? Can I delete 3.0 and keep 6.0 which I assume is a later version.