msiexec /x "C:Table Manager Clients.msi" /quiet /qn

msiexec /Option <Required Parameter> [Optional Parameter]
   
Install Options
    </package | /i> <Product.msi>
        Installs or configures a product

MsiExec.exe /X{4B9E6EB0-0EED-4E74-9479-F982C3254F71}

Private Sub UninstallMsi(productName As String)
    Dim reg_path As String = "SOFTWAREMicrosoftWindowsCurrentVersionInstallerUserDataS-1-5-18Products"
 
    Dim key As RegistryKey = Registry.LocalMachine.OpenSubKey(reg_path)
 
    For Each temp_key_name As String In key.GetSubKeyNames()
        Dim temp_key As RegistryKey = key.OpenSubKey(temp_key_name & "InstallProperties")
 
        If temp_key IsNot Nothing Then
            If temp_key.GetValue("DisplayName").ToString.Trim.ToLower = productName.Trim.ToLower Then
 
                Dim uninstall_string As String = temp_key.GetValue("UninstallString").ToString
 
                uninstall_string = uninstall_string.ToLower.Replace("msiexec.exe", "").Replace("msiexec", "").ToUpper
 
                uninstall_string = uninstall_string.Replace("/I", "/x")
                uninstall_string = uninstall_string.Replace("/i", "/x")
 
                uninstall_string &= " /quiet /qn"
 
                Console.WriteLine("Uninstalling product " & uninstall_string)
                LogDataAccess.InsertApplicationLog(TMConfigrationManager.GetConfig("ServerType"), _
                                                 "Uninstalling " & productName & """" & uninstall_string & """ ...")
 
                Dim proc_start_info As New ProcessStartInfo("msiexec", uninstall_string)
 
                Dim proc As Process = Process.Start(proc_start_info)
 
                If (proc IsNot Nothing) Then proc.WaitForExit()
                If proc.ExitCode <> 0 Then
                    Dim err_message As String = "Uninstall " & productName & " failed."
 
                    LogDataAccess.InsertApplicationLog(TMConfigrationManager.GetConfig("ServerType"), err_message)
                    Console.WriteLine(err_message)
                End If
 
                LogDataAccess.InsertApplicationLog(TMConfigrationManager.GetConfig("ServerType"), "Uninstall previous version of " & productName & " successful.")
 
                Exit Sub
            End If
        End If
    Next
 
    Dim message As String = "Cannot find " & productName & " registry entries. Do not need to uninstall."
 
    LogDataAccess.InsertApplicationLog(TMConfigrationManager.GetConfig("ServerType"), message)
    Console.WriteLine(message)
End Sub