Thanks, Andrei. I tried disabling all IE add-ons, and it helped in one way but not in another. The Orange CD program still took a full six minutes (!) to load; however, once it was loaded, it ran very fast. So I suspect that the base problem is not the add-ons, but a security patch or malware that downloaded to my laptop on December 30. That would have been a Microsoft "Patch Tuesday," but the only 12/30 update I see in my "Add or Remove Programs" list is Windows Genuine Advantage Notifications KB905474, which I cannot disable.

I suppose that if a difficulty with that update comes to Microsoft's attention, they'll patch the patch; that happens all the time.