if you have some .NET program and wish to tell a user if he needs or not to
install .NET BEFORE he downloads your application, simply use javaScrip to
see if he has .NET and which version.
this will BTW work also without a webserver. so you can use such html page
in a downloaded zip file.
check this page (source of the script can be found in the page)..:
http://www.freewebs.com/yellowfox/dotnet/
best of luck.
BTW, if someone has stats regarding how many users have .NET (when looking
only on IEx users) pls post it here...