启动已注册的mime帮助应用程序

I used to be able to launch a locally installed helper application by registering a given mime-type in the Windows registry. This enabled me to allow users to be able to click once on a link to the current install of our internal browser application. This worked fine in Internet Explorer 5 (most of the time) and Firefox but now does not work in Internet Explorer 7.I used to be able to launch a locally installed