How can I Detect software installed in a client machine

Below is a complete code I wrote...
Note: some programs do not have a displayName. but most valid software tools do.
In the program below, the disName is what you want to look at.
I have added 2 columns to a listview in the GUI, and set the properties:
listview1.view=details
etc
but you may as well use a listbox or textbox...

cheers

Option Explicit On
Imports Microsoft.Win32
'Created by Kourosh Parsa
 
Public Class Form1
 
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim path As String = "SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall"
        Dim objParent As RegistryKey
        Dim objSubkey As RegistryKey
 
        Try
            objParent = Registry.LocalMachine
            objSubkey = objParent.OpenSubKey(path, False)
 
            Dim subNames As String() = objSubkey.GetSubKeyNames()
            For Each str As String In subNames
                Dim disName As String = ""
                Dim item As RegistryKey = Registry.LocalMachine.OpenSubKey(path + "\" & str)
                If Not item.GetValue("DisplayName", "") Is "" Then
                    ' DisplayName is the name of the program installed.
                    DisName = (CType(item.GetValue("DisplayName", ""), String))
                End If
 
                ListView1.Items.Add(disName).SubItems.Add(path & "\" & str)
            Next
 
 
        Catch ex As Exception
            MsgBox("Error" & vbNewLine & ex.Message)
        End Try
 
    End Sub
End Class

Select allOpen in new window

To detect if the application is running, you can use the Process class's GetProcessesByName() method
http://msdn.microsoft.com/en-us/library/system.diagnostics.process.getprocessesbyname(VS.80).aspx 

This Looks fine for a Windows app, but It will not work for a client. My app is a web app (ASP.NET). Do you have anything for doing this but on the client side?
 

But still I have to depend on the client to allow this to access the register.
Is there anything else that allows me to check for a program installed on the client. maybe using javascript?
If there is nothing, How are handling this so that it does not crash?

Anything else?