C# class to impersonate user

Problem 1: I am looking for a C# class that I can use to launch a program in an interactive user session if I am currently running in the SYSTEM context/session 0. I want something that will work on Windows XP and higher. The goal is to use this class to display a GUI to users when running in the SYSTEM context. I essentially want this powershell script to be written as a C# class: [login to view URL] I want the following additional options that the powershell script does not provide: a) Be able to specify the session # that I want the program to open under. b) Specify whether the process should be launched with an admin token or a standard user token. I'm not sure if you would have to enumerate and return both admin and standard tokens and then use choose the one specified or if you can adjust admin tokens so that they become user tokens. The PowerShell script currently only returns an admin token if both an admin and a standard token exist. c) On line 1443, it currently filters out local services by username. This will not work for non-english languages. I would like this filter to by by SID. I believe the SID for a LOCAL SERVICE is S-1-5-19. d) On line 1690, a WMI method is used to discover the porcess owner username and then it's compared to the SYSTEM account username to see if they are the same. I would rather discover the process owner SID and compare that to the SYSTEM account SID. Also, I would rather use the Win32 method of discovering the process owner SID as it is much faster than WMI: [login to view URL] Problem 2: The QueryUser class and the GetUserSessionInfo function located here discover all logged in users and details about them: [login to view URL] On line 559, it discovers all local admins in the local administrator's group. Instead of using this method, I would like to be able to examine the token for a user to see if they are in the local administrator's group. I would also like to be able to use the token to see if they belong to any other admin type such as domain admin. Links for reference that I found while researching this topic: [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL] [login to view URL]