Hi mg:
Let me try to explain what is happening.
ASP.NET is a server side process and by default runs under a different
Windows account (typically the ASPNET account) than a user would use.
When you start a process from an ASP.NET page it will launch for the
ASPNET user (you'll probably find Notepad in the list of running
processes in task manager), but ASPNET does not interact with the
desktop (the user interface), so notepad doesn't appear.
If you think about it, this makes sense. If I hit msn.com with a web
browser it doesn't make any sense for msn to launch notepad on thier
server. Even it showed up on the server's desktop I wouldn't be able
to see it from my computer. It's server side code and a server side
process.
If you want to launch notepad on the client machine, you'll need to
use client side script, but you'll need the client to trust you first
because noone wants websites to launch processes on thier machine
willy nilly.