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#include<Winbase.h>
 
BOOL IsUserAdmin(VOID);
 
int main()
{
   IsUserAdmin();
 
   return 0;
}
 
 
BOOL IsUserAdmin(VOID)
{
BOOL b;
SID_IDENTIFIER_AUTHORITY NtAuthority = SECURITY_NT_AUTHORITY;
PSID AdministratorsGroup; 
b = AllocateAndInitializeSid(
    &NtAuthority,
    2,
    SECURITY_BUILTIN_DOMAIN_RID,
    DOMAIN_ALIAS_RID_ADMINS,
    0, 0, 0, 0, 0, 0,
    &AdministratorsGroup); 
if(b) 
{
    if (!CheckTokenMembership( NULL, AdministratorsGroup, &b)) 
    {
         b = FALSE;
    } 
    FreeSid(AdministratorsGroup); 
}
 
return(b);
}