You can prevent activeX components from being installed by setting one of the internet explorer security options. Sorry, I can't remember which one it is & can't find out at the moment as I'm using a Linux laptop using a Netscape browser.
As I've never to my knowledge installed a badly behaved activeX component, I've never had to delete one. You could use the
http://www.google.com search engine to look for details - try using keywords like
remove activex component
[This message has been edited by mik (edited 14 November 2000).]