Bin ich Admin?
LCC-Compiler wird benötigt.
alle Dateien in ein Verzeichnis kopieren.
dann :

make
checkadmin.exe

checkadmin.c

// checkt den angemeldeten Benutzer auf Administrator // borwinius
/*<---------------------------------------------------------------------->*/
#include <windows.h>
#include <windowsx.h>
#include <commctrl.h>
#include <string.h>
#include <wchar.h>
#include <tchar.h>
#include "checkadminres.h"
 
/*<---------------------------------------------------------------------->*/
#define ACCESS_READ  1
#define ACCESS_WRITE 2
 
 
HINSTANCE hInst; //globale Instanz
BOOL bAdm; 		//sein oder nicht sein
char cUser[128];//Benutzername
ULONG ulU = 128;//Länge des bn
 
static BOOL CALLBACK DialogFunc(HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam);
BOOL IsAdmin(void); //prüft ob der User Admin ist
 
//--------------------------------------------------------------------------
int APIENTRY WinMain(HINSTANCE hinst, HINSTANCE hinstPrev, LPSTR lpCmdLine, int nCmdShow)
{
	WNDCLASSEX wc;
	INITCOMMONCONTROLSEX cc;
 
	memset(&wc,0,sizeof(wc));
	wc.lpfnWndProc = DefDlgProc;
	wc.cbWndExtra = DLGWINDOWEXTRA;
	wc.hInstance = hInst = hinst;
	wc.hCursor = LoadCursor(NULL, IDC_ARROW);
	wc.hbrBackground = (HBRUSH) (COLOR_WINDOW + 1);
	wc.lpszClassName = " checkadmin";
	RegisterClassEx(&wc);
	wc.hIcon	= LoadIcon(hinst,"JSICON");
	wc.hIconSm  = wc.hIcon;
 
	memset(&cc,0,sizeof(cc));
	cc.dwSize = sizeof(cc);
	cc.dwICC = 0xffffffff;
	InitCommonControlsEx(&cc);
 
	return DialogBox(hinst, MAKEINTRESOURCE(IDD_MAINDIALOG), NULL, (DLGPROC) DialogFunc);
 
}
//--------------------------------------------------------------------------
/*
You should add your initialization code here. This function will be called
when the dialog box receives the WM_INITDIALOG message.
*/
static int InitializeApp(HWND hDlg,WPARAM wParam, LPARAM lParam)
{
	bAdm = IsAdmin();
	GetUserName(cUser,&ulU);
	SetClassLong(hDlg,GCL_HICON,(LONG)LoadIcon(hInst,"JSICON"));//Icon in Dialogbox
 
	return 1;
}
//--------------------------------------------------------------------------
// DialogNachrichtenfunktion
static BOOL CALLBACK DialogFunc(HWND hwndDlg, UINT msg, WPARAM wParam, LPARAM lParam)
{
 
	switch (msg) {
 
	case WM_INITDIALOG:
		InitializeApp(hwndDlg,wParam,lParam);
 
		if(bAdm)
		{
		SetDlgItemText(hwndDlg,ID_MESSAGE,"Sie sind schon lokaler Administrator !!!");
		SetDlgItemText(hwndDlg,ID_TEXT,"\n\nSeien Sie deshalb vorsichtig !");
		}
 
		return TRUE;
 
	case WM_COMMAND:
		switch (LOWORD(wParam)) {
			case IDOK:
				EndDialog(hwndDlg,1);
				return 1;
		}
		break;
        /* By default, WM_CLOSE is equivalent to CANCEL */
	case WM_CLOSE:
		EndDialog(hwndDlg,0);
		return TRUE;
 
	}
	return FALSE;
}
//------------------------------------------------------------------------------
//Output:        Return TRUE wenn user Administrator oder FALSE wenn nicht.
// Errors:        Return FALSE.
 
BOOL IsAdmin(VOID)
{
	HANDLE hToken;
	DWORD  dwStatus;
	DWORD  dwAccessMask;
	DWORD  dwAccessDesired;
	DWORD  dwACLSize;
	DWORD  dwStructureSize = sizeof(PRIVILEGE_SET);
	PACL   pACL            = NULL;
	PSID   psidAdmin       = NULL;
	BOOL   bReturn         = FALSE;
	PRIVILEGE_SET   ps;
	GENERIC_MAPPING GenericMapping;
	PSECURITY_DESCRIPTOR     psdAdmin           = NULL;
	SID_IDENTIFIER_AUTHORITY SystemSidAuthority = SECURITY_NT_AUTHORITY;
 
	if(!ImpersonateSelf(SecurityImpersonation))
		goto LeaveIsAdmin;
 
	if (!OpenThreadToken(GetCurrentThread(), TOKEN_QUERY, FALSE, &hToken))
	{
		if (GetLastError() != ERROR_NO_TOKEN)
			goto LeaveIsAdmin;
 
		if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken))
			goto LeaveIsAdmin;
 
		if (!OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &hToken))
			goto LeaveIsAdmin;
	}
 
	if (!AllocateAndInitializeSid(&SystemSidAuthority, 2,
		SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS,
		0, 0, 0, 0, 0, 0, &psidAdmin))
		goto LeaveIsAdmin;
 
	psdAdmin = LocalAlloc(LPTR, SECURITY_DESCRIPTOR_MIN_LENGTH);
	if (psdAdmin == NULL)
		goto LeaveIsAdmin;
 
	if (!InitializeSecurityDescriptor(psdAdmin,
		SECURITY_DESCRIPTOR_REVISION))
		goto LeaveIsAdmin;
 
	dwACLSize = sizeof(ACL) + sizeof(ACCESS_ALLOWED_ACE) +
	    GetLengthSid(psidAdmin) - sizeof(DWORD);
 
	pACL = (PACL)LocalAlloc(LPTR, dwACLSize);
	if (pACL == NULL)
		goto LeaveIsAdmin;
 
	if (!InitializeAcl(pACL, dwACLSize, ACL_REVISION2))
		goto LeaveIsAdmin;
 
	dwAccessMask= ACCESS_READ | ACCESS_WRITE;
 
	if (!AddAccessAllowedAce(pACL, ACL_REVISION2, dwAccessMask, psidAdmin))
		goto LeaveIsAdmin;
 
	if (!SetSecurityDescriptorDacl(psdAdmin, TRUE, pACL, FALSE))
		goto LeaveIsAdmin;
 
	if(!SetSecurityDescriptorGroup(psdAdmin, psidAdmin, FALSE))
		goto LeaveIsAdmin;
	if(!SetSecurityDescriptorOwner(psdAdmin, psidAdmin, FALSE))
		goto LeaveIsAdmin;
 
	if (!IsValidSecurityDescriptor(psdAdmin))
		goto LeaveIsAdmin;
 
	dwAccessDesired = ACCESS_READ;
 
	GenericMapping.GenericRead    = ACCESS_READ;
	GenericMapping.GenericWrite   = ACCESS_WRITE;
	GenericMapping.GenericExecute = 0;
	GenericMapping.GenericAll     = ACCESS_READ | ACCESS_WRITE;
 
	if (!AccessCheck(psdAdmin, hToken, dwAccessDesired,
		&GenericMapping, &ps, &dwStructureSize, &dwStatus, &bReturn))
		goto LeaveIsAdmin;
 
	if(!RevertToSelf())
		bReturn = FALSE;
 
LeaveIsAdmin:
 
	if (pACL) LocalFree(pACL);
	if (psdAdmin) LocalFree(psdAdmin);
	if (psidAdmin) FreeSid(psidAdmin);
 
	return bReturn;
}
//------------------------------------------------------------------------------

checkadmin.rc

/* Wedit generated resource file */
#ifdef __LCC__
#include <windows.h>
#endif
#include "checkadminres.h"
 
 
IDD_MAINDIALOG DIALOG 7, 20, 195, 94
STYLE DS_CENTER | DS_SETFOREGROUND | WS_POPUP | WS_VISIBLE | WS_CAPTION | WS_SYSMENU
CAPTION " checkadmin / richard@borwinius.de"
FONT 8, "Helv"
BEGIN
    DEFPUSHBUTTON   "OK", IDOK, 51, 71, 97, 14
    CTEXT           "Sie sind kein Administrator !", ID_MESSAGE, 8, 6, 181, 12
    CTEXT           "\n\nTut mir leid", ID_TEXT, 8, 21, 181, 46, SS_SUNKEN
END
//JSICON ICON "js.ico"

checkadminres.h

/* Weditres generated include file. Do NOT edit */
#include <windows.h>
#define	IDD_MAINDIALOG	100
#define	ID_MESSAGE	101
#define	ID_TEXT	102

Makefile

# Wedit Makefile for project checkadm
 
CFLAGS=-Ic:\programme\lcc\include  -O  -A  -unused
CC=$(LCCROOT)\bin\lcc.exe
LINKER=$(LCCROOT)\bin\lcclnk.exe
OBJS=\
	checkadmin.res \
	checkadmin.obj
 
EXE=checkadm.exe
 
$(EXE):	$(OBJS) Makefile
	$(LINKER)  -s -subsystem windows -o checkadm.exe $(OBJS)
 
# Build checkadmin.res
CHECKADMIN_RC=\
	   checkadminres.h\
 
checkadmin.res:	$(CHECKADMIN_RC) checkadmin.rc
	$(LCCROOT)\bin\lrc.exe -Ic:\programme\lcc\include  checkadmin.rc
 
# Build checkadmin.c
CHECKADMIN_C=\
	   checkadminres.h\
 
checkadmin.obj: $(CHECKADMIN_C) checkadmin.c
	$(CC) -c $(CFLAGS) checkadmin.c
 
link:
	$(LINKER)  -s -subsystem windows -o checkadm.exe $(OBJS)
 
clean:
	del $(OBJS) checkadm.exe