I have Win XP Home 2002 and Word 2000. I installed the Add-In today. I should have read the version instructions, but was focused on a different problem (silly, I know). Shortly after, I found that when I opened Word 2000, the program would hang. The border was there in some fashion, but the menu buttons would not show up. The Task Manager showed Word not responding. (Curiously, Excel 2000 started up fine. I didn't attempt to open any other Office 2000 programs.)
I finally managed to remove the Add-In from the Add/Remove Programs control panel. Now, Word is functioning normally again.
Along the way, I tried using Spybot to remove the Browser Helper Object associated with the Add-In. FYI, this did not help.
I should probably add with appropriate sheepishness that my hard drive is pretty crowded. Some conflicts have more dire effects on my system than they would on one with more resources.