Each ActiveX author to update or correct why their application does not work. If all ActiveX applications fail you might have IE8's security set to a high lever (a good thing.)
Not to offer any tutorial on where the activex options are, be sure to explore them all.
For reasons I won't go into, I had problems with my Win7 Premium upgrade over Vista Basic. So I did a clean install. There are a few quirky things now, the most irritating being the inability to use ActiveX controls from Web sites (i.e., running a PC Pit Stop scan). There are postings all over the place, so I know I'm not the only one. I have rejiggered every conceivable setting under custom settings in IE8, and it just doesn't work. No controls come up, no prompts, no nuttin.
Any thoughts or suggestions?