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Run a application under current logged in user without passing credentials

I am using redmon to redirect print job to my application.exe which is built in c#, its working fine with single user (on computer) but when i have another user on computer and i use it, redmon (which always run on system context) run's my application.exe in system context so i see my exe in taskbar but it don't show any UI where was on single user machine it runs my application under user-context so i am able to see my application open.
This whole problem of redmon is with windows 10 multiple user only
Now my plan is that i create an adapter in between in which i will create a exe which will be run by redmon in system context and then that exe run my application.exe in current loggedin user-context and i see UI of my application and interact with it.
I googled for it and every solution is using username and password and in my case i don't know who all would be using it and i won't be asking username/pass from users so i just want to run my exe using c# under current logged in user-context without passing username/pass.
please help me with that.
I have tried this code as well but its not running exe though it is returning True https://chasewright.com/2015/12/26/session0bypass/
NOTE: I am working on Active Directory environment.

File System watcher in Windows Service or Console Application?

I am implementing a file system watcher, my requirement is to watch for a given local folder on a machine and then do a small task (for example open a certain page in web browser). The file(s) in the given directory would be generated randomly sometimes every two hours or four etc. This tool should be automated in the sense that a user does not have to start it. So my question is, Should I implement this in a windows service which always will be running or in a console application.Preference is to do it in a console application but then it would need to started by a user right? Please advice

You can automatically call any type of application (Console, Windows, etc.). What it gets down to with a Windows Service is whether you want it to be running before anyone logs in.
Only a Windows service runs while no one is logged in. A console application (while it can be set to run on login) must have someone log in in order to run.

Running a program when Windows Boots (before Login)

I wonder is it possible to run my application before login on windows.? Its actually a WinForm application(Preferably other than Windows service).
I mean my application must be running even before log in and it should sit on System Tray from which I can "show" or open Interface for user.

To have:
Something happen between system startup and user login
An icon in the notification area for users to interact with
You must break your application up into two separate components. One of these will be a WinForms/WPF application which provides the notification area icon and allows the user to interact with it. The other will be a Windows Service, or possibly a scheduled task.
Once you've done this, the windows service can focus on doing whatever needs to be done prior to logon and the notification area application can assume responsibility for showing the results, or whatever else to the end user.
To answer the question you posed in comments regarding reading data from the Event Log, yes this is possible. There are other questions on here which will give you that particular answer:
read the windows event log by particular Source
Read event log in C#

This MS article might help but it is a bit old:
http://support.microsoft.com/kb/142905
Hopefully it'll put you on the right tracks though.

I think, it doesn't make sense, to acquire user input before a user has logged into the system. So, if the application needs input from a user, why start it before the use has logged in? If the application just starts some background work, than you should use a windows service, as this is the prefered way in windows.

Type in run gpedit.msc, for Group Policy,
There you can set start up script.
Application will launch before Windows Login,
Step to produce :-
Start --> Run --> gpedit.msc --> Local Computer Policy --> Windows Settings --> Script (Startup/ShutDown),
Add you .exe
It will launch Before login.
Do not try more in Group Policy, it may happen harmful for System
By Programmatic logic,
Try with registry key
this value is updating in registry,
by our program we can update directly registry then we can call application

You can schedule any application to be run when computer is powered on using Windows Task Scheduler. There is a corresponding option there.
But why would you need this? You should use a service for this.

Granting administrator privileges to an application launched at startup without UAC prompt?

Background
I've written a small C#/.NET 4.0 application that syncs various settings from a game installed in Program Files to and from other copies of the same game on different machines (think Chrome bookmark sync, but for this game). The sync itself is a relatively simple affair, dealing with files stored inside the game's Program Files folder.
On my machine, this works fine without having to elevate my application through UAC. Windows 7 makes the game use Program Files virtualisation and my application works fine with that.
However, on a lot of tester's machines, I'm getting reports that the application either can't work with the files and in come cases can't even see the game's folder! Having the user right-click and "Run as Administrator" solves the problem in every case.
So, we just set the application's manifest to require admin privileges, right? That's fine (although not ideal) for when the user manually invokes the application or the sync process because they'll be interacting with the application and ready to accept a UAC request.
However, one of the features of my application is a "Sync Automatically" option, which allows the user to "set and forget" the application. With this set, the application puts itself into the registry at HKCU\Software\Microsoft\Windows\CurrentVersion\Run to be run at startup and sits in the system tray syncing the settings in the background as needed.
Obviously, I need to be smarter here. Presenting a UAC prompt as soon as the user logs in to their account or at random intervals afterwards isn't the way forwards.
So, my question!
What's the best way to approach a situation where I'd need to run an application at startup that needs administrator privileges? Is there a way to have the user authorise an installation that causes the system to automatically run the application with the correct privileges without a prompt at startup/login?
Update Just to be clear, this must be achievable in code.

You should consider making your Sync functionality exist within a Windows Service.
This is the preferred method for running 'background' functionality on Windows.
The Service can either run under the user's account (assuming they have permissions to modify the files), or you can use another account which does. Worst case, you can run as SYSTEM (although, this isn't best practice).
If you've already got your background process functionality working, then this should be a simple process to convert over to a Service.
There's a sample project here that will set you on the right path: http://www.codeproject.com/KB/dotnet/simplewindowsservice.aspx

Since you mentioned running at startup, why not use a scheduled task instead of what you're doing with the registry? You can set them up from code - there's a project on CodePlex that is basically a managed wrapper to save you having to do the PInvokes yourself. You run your little "set up the startup task" app elevated, and it specifies that the app should launch elevated, and the user won't even be prompted. I believe that's the answer to the question in your last paragraph.

I would use Security namespace and check inline for the user roles.
using System.Threading;
using System.Security.Principal;
namespace StackOverflow_Demo
{
class Program
{
static void Main(string[] args)
{
AppDomain.CurrentDomain.SetPrincipalPolicy(PrincipalPolicy.WindowsPrincipal);
WindowsPrincipal currentPrincipal = (WindowsPrincipal) Thread.CurrentPrincipal;
if (currentPrincipal.IsInRole("Administrators"))
{
// continue programm
}
else
{
// throw exception/show errorMessage - exit programm
}
}
}
}
The currentUser may start your application and will get an info message if he is not member of admininistrator role!
Hope this may help!

Running application on Startup under different User

I have a .Net app that i install and set to run at Startup. The installer also creates a user that has write permissions to the appropriate application folders and registry sections, preventing the currently running user from modifying the restricted areas.
However, i am unable to figure out how to run the application under a different user. It's not a Service (although that is a possibility). I'm really trying to figure out how to do the following:
Start an application on boot as a different user.
Install a service to start on boot, as a different user.
Can anyone point me in the right direction?
Regards
Tris

With respect to services, you specify the user they run as when you install one.
To start an app as someone else, you could create a batch script that launches your app with the RUNAS command, though I believe you are prompted for a password so it may not be what you're after.