how to launch an exe from browser ?

Hi,

I have written an Activex DLL and packed it as Cab file and marked it as safe for scripting. This will be launched from the webbrowser as follows :

<HTML>
<HEAD>
<TITLE>Chatroom.CAB</TITLE>
</HEAD>
<BODY>
<OBJECT ID="ChatTest"
CLASSID="CLSID:D02F7572-AED3-4F80-A58A-213C3A60BC91"
CODEBASE="Chatroom.CAB#version=1,0,0,0">
</OBJECT>

<script language="javascript">

</script>
</BODY>
</HTML>

So, This cab file consists of dependencies of this activex as well as a EXE file name a.exe.
the LaunchRoom function in Activex is supposed to launch that a.exe.
But where this file will be saved, when activex is installed from browser ?
what is the default path for it ?

Thanks in advance.

Thanks & Regards
Chinna