For Firefox, it is possible to detect if a Firefox extension is installed using JavaScript by checking whether a specific image is existing on chrome://. But, how can i do the detection on Internet Explorer for an Internet Explorer plugin using JavaScript or others.
Thanks.
Im not sure wich plugin you want to detect, but this might help you
http://www.builtfromsource.com/2007/06/26/detecting-plugins-in-internet-explorer-and-a-few-hints-for-all-the-others/
EDIT: Original link is 404
http://www.matthewratzloff.com/blog/2007/06/26/detecting-plugins-in-internet-explorer-and-a-few-hints-for-all-the-others/
EDIT: Internet Archive to the rescue
https://web.archive.org/web/20170806025526/http://www.matthewratzloff.com/blog/2007/06/26/detecting-plugins-in-internet-explorer-and-a-few-hints-for-all-the-others/