In our old ASP web site we have an ActiveX control written in VB6 that writes
a structured file to the users floppy disk drive.

Now that we are updating the site to ASP.NET, I want to rewrite the ActiveX
control in C#.NET.

I created a solution with a ASP.NET Web App project and a Windows Control
Library project containing a simple user control with a button on it.

The control assembly is signed, and I have the <object> tag to include the
control on the default.aspx page. This works fine on my own PC. When I open
the url I see the ActiveX control with the button. Of course, I have to
"click to activate activex control", which is fine, and once done I can click
the button to create the file.

However, on other users PC's, they don't see the control. Just a box with a
small icon in it. They are not prompted or otherwise informed of how to get
it to work.

What I would really like is for it to behave the way that other ActiveX
controls do, in that it would show the information bar in IE7, giving the
option to download the activeX control, and then show the install dialog.

Do I need to do anything special with the Windows Control Library project to
get it to work that way?