Which programming language?

Actually, the programming language used does not play a big role, so you have access to a Framwork that provides GUI functionality.

Under .Net is usually Form.

In C# a simple demo would look like this:

Demo.cs

using System;
using System.Drawing;
using System.Windows.Forms;
using System.Runtime.InteropServices;

public class Form1 : Form {
    private Button Button1;  
    private Label Display1;

      //Native Funktion  zum setzen der aktiven Powershemas
    [DllImport("PowrProf.dll", CharSet = CharSet.Unicode)]
    static extern UInt32 PowerSetActiveScheme(IntPtr RootPowerKey,Guid SchemeGuid);


    private Guid HeighProfile = Guid.Parse("8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c");


    public Form1() {
        this.Size = new Size(600,140);


        Display1 = new Label();
        Display1.Text = "Irgendein Text";
        Display1.Location = new Point(10, 20);
        Display1.AutoSize = true;
        this.Controls.Add(Display1);
        
        Button1 = new Button();
        Button1.Text = "Setze Höchstleistung";
        Button1.Location = new Point(10, 40);
        Button1.AutoSize = true;
        Button1.Click += new System.EventHandler(Button1_Click);
        this.Controls.Add(Button1);
    }

    private void Button1_Click(object sender, EventArgs e){ 
        Display1.Text = "Jetz  sollte  Höchstleitun aktiv  sein";
        PowerSetActiveScheme(IntPtr.Zero,HeighProfile);
    }
    
    static void Main() {
        
            Application.EnableVisualStyles();
            Application.Run(new Form1());
    }
}

the same thing in Powershell:

demo.ps1

 #console ausblenden
$user32=Add-Type -m '[DllImport("user32.dll")] public static extern void ShowWindow(IntPtr hWnd, int nCmdShow);' -Name myAPI -passthru
$hwnd=(gps -id $PID).MainWindowHandle
$user32::ShowWindow($hwnd, 0)


Add-Type -AssemblyName System.Windows.Forms

$Form = New-Object System.Windows.Forms.Form
$Form.Text = 'Irgendwas'
$Form.Size = '600,140'

$Display1 = New-Object System.Windows.Forms.Label
$Display1.Location = '10,10'
$Display1.Text   = 'Irgendein Text'
$Display1.AutoSize = $True;
$Form.Controls.Add($Display1)

$Button1 = New-Object System.Windows.Forms.Button
$Button1.Location = '10,40'
$Button1.Text = 'Setze Hoechstleistung'
$Button1.AutoSize = $True

$Button1_Action={
    $Button1.Enabled = $False
    $Display1.Text = "Jetz  sollte  Hoechstleitung aktiv  sein"
      #da es kein Problem ist Powershell von Consol-Befehlen  gebrauch zu  machen, einfach den bequemsten  Weg  nutzen
    powercfg /setactive 8c5e7fda-e8bf-4a96-9a85-a6e23a8c635c   #setze  Höchstleistung
}
$Button1.Add_Click( $Button1_Action )
$Form.Controls.Add($Button1)

$Null=$Form.ShowDialog()

On a Windows computer it is of course easiest to program small projects with C# or Powershell.

Theoretically you don’t even need Visual Studio a simple compiler “csc.exe” located on any Windows system.

Here is a small batch with which you can compile small C# programs with .Net-Framework 4.8:

compile.cmd

@echo off
chcp 65001 >nul
if "%~1"=="" (
    echo C# Compiler-Batch.
    echo:
    echo Ziehe eine Datei mit C#-Source auf "%~nx0" ...
    timeout 7
    exit /b
)
for /f "tokens=* delims=" %%v in ('dir /b /s /a:-d  /o:-n "%SystemRoot%\Microsoft.NET\*csc.exe"') do (
set "csc=%%v"
)
if "%csc%"==""  (
    echo Kein C#-Compiler gefunden
    echo Bitte installiere Microsoft-.NetFramework!
    pause
exit /b
) else (
    echo "%csc%" gefunden.
)


set "WPF_Path=C:\Windows\Microsoft.NET\Framework64\v4.0.30319\WPF"
set "WPF_Speech=/reference:%WPF_Path%\system.speech.dll"
set "WPF_Media=/reference:%WPF_Path%\PresentationCore.dll"
set "WPF_WindowBase=/reference:%WPF_Path%\WindowsBase.dll"
set "Platform=/platform:anycpu"


set "Switches=/nologo %Platform% %WPF_Speech% %WPF_Media% %WPF_WindowBase%"
rem teste ob es sich um eine Windowsformsaplikation handeln könnte
for /f "tokens=*" %%a in ('type "%~f1" ^|findstr /irc:"using  *System\.Windows\.Forms *;" /c:"static  *....*  *Main *(.*)" /c:"Application.Run *(.*)"') do @(
  set /a "IsWinApp+=1"
  echo %%a |find /i "Main">nul &&(set "IsApp=1")
)


if "%IsWinApp%" == "3" (call :AskCompileWinApp)
if "%IsApp%" neq "1" (goto :NoApp)


set "inputFile=%~f1"
set "outputFile=%~dpn1.exe"
call:compile  %Switches%  -out:"%outputFile%" "%inputFile%" && (
    echo Hat geklappt...
    echo ...." %~dpn1.exe"...
    echo Ausgabe Deines Programms:
    cd /d "%~dp1"
    echo:
    "%~dpn1.exe"
    echo:
) || (
    echo Compilererror...
    echo:
    type compile.log
    echo:
)
pause
exit /b
::::::::: subroutines
:compile 
"%csc%" %* >compile.log
exit /b


:AskCompileWinApp
echo:
echo possible WindowsApplication
echo Compile as WindowsGUIApp without Console?
choice /c yn /t 1 /d y 
if %errorlevel% equ 1 (set Switches=%Switches% /target:winexe)
exit /b
:NoApp
echo Maybe an Library?
echo Doing nothing  jet!
pause

simply drag a .cs file to the batch…