Setting Environment Variables in .NET

Question

I need a way of setting environment variables on the fly in C#. I have found a way using the registry but I have to reboot my machine before it becomes available to read. See below =============== public static bool setEnvVar(string name, string Value) { try { //check the parameters if(name!=null && Value!=null) { RegistryKey key1=Registry.LocalMachine .CreateSubKey(@"SYSTEM\ControlSet001\Control\Session Manager\Environment"); ; key1.SetValue(name,Value); return true; } else { MessageBox.Show("The parameters for the setEnvVar function were invalid"); return false; } } catch(Exception ex) { MessageBox.Show("Exception in setEnvVar "); MessageBox.Show(ex.Message); return false; } } ============== Is there a way to do it so it become available straight away (like using the cmd window) ? There only seems to be Reading Env Variables defined in .NET Can someone help?