Sometimes we need determine when a windows version is a server edition (2000, 2003 or 2008) or a Desktop edition. to do this we can use the VerifyVersionInfo function. this function compares a set of operating system version requirements to the corresponding values for the currently running version of the system.

but exist a problem, the version of this function declared in the Windows unit uses a OSVERSIONINFO parameter.

function VerifyVersionInfo(var lpVersionInformation: TOSVersionInfo;
  dwTypeMask: DWORD; dwlConditionMask: DWORDLONG): BOOL; stdcall; 

And in this case we need pass a OSVERSIONINFOEX Structure, so we must re-declare this function in this way.

{$IFDEF UNICODE}
function VerifyVersionInfo(var LPOSVERSIONINFOEX : OSVERSIONINFOEX;dwTypeMask: DWORD;dwlConditionMask: int64): BOOL; stdcall; external kernel32 name 'VerifyVersionInfoW';
{$ELSE}
function VerifyVersionInfo(var LPOSVERSIONINFOEX : OSVERSIONINFOEX;dwTypeMask: DWORD;dwlConditionMask: int64): BOOL; stdcall; external kernel32 name 'VerifyVersionInfoA';
{$ENDIF}

Now to work with the VerifyVersionInfo function we need establish the requirements to check .

   ZeroMemory(@osvi, sizeof(OSVERSIONINFOEX));
   osvi.dwOSVersionInfoSize := sizeof(OSVERSIONINFOEX);
   osvi.dwMajorVersion := 5; //at least windows 2000
   osvi.dwMinorVersion := 0;
   osvi.wServicePackMajor := 0;
   osvi.wServicePackMinor := 0;
   osvi.wProductType := VER_NT_SERVER; // Check windows server edition

then we need set the flags to interrogate the VerifyVersionInfo function using the VerSetConditionMask function

   op:=VER_GREATER_EQUAL;
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_MAJORVERSION, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_MINORVERSION, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_SERVICEPACKMAJOR, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_SERVICEPACKMINOR, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_PRODUCT_TYPE, VER_EQUAL );

and finally call the function in this way

   VerifyVersionInfo(osvi,VER_MAJORVERSION OR VER_MINORVERSION OR
      VER_SERVICEPACKMAJOR OR VER_SERVICEPACKMINOR OR VER_PRODUCT_TYPE, dwlConditionMask);

This is the source code of the demo console application.

program ISWindowsServer;

{$APPTYPE CONSOLE}

uses
  Windows,
  SysUtils;

{$IFDEF UNICODE}
function VerifyVersionInfo(var LPOSVERSIONINFOEX : OSVERSIONINFOEX;dwTypeMask: DWORD;dwlConditionMask: int64): BOOL; stdcall; external kernel32 name 'VerifyVersionInfoW';
{$ELSE}
function VerifyVersionInfo(var LPOSVERSIONINFOEX : OSVERSIONINFOEX;dwTypeMask: DWORD;dwlConditionMask: int64): BOOL; stdcall; external kernel32 name 'VerifyVersionInfoA';
{$ENDIF}
function VerSetConditionMask(dwlConditionMask: int64;dwTypeBitMask: DWORD; dwConditionMask: Byte): int64; stdcall; external kernel32;

function IsWinServer : Boolean;
const
   VER_NT_SERVER      = $0000003;
   VER_EQUAL          = 1;
   VER_GREATER_EQUAL  = 3;
var
   osvi             : OSVERSIONINFOEX;
   dwlConditionMask : DWORDLONG;
   op               : Integer;
begin
   dwlConditionMask := 0;
   op:=VER_GREATER_EQUAL;

   ZeroMemory(@osvi, sizeof(OSVERSIONINFOEX));
   osvi.dwOSVersionInfoSize := sizeof(OSVERSIONINFOEX);
   osvi.dwMajorVersion := 5;
   osvi.dwMinorVersion := 0;
   osvi.wServicePackMajor := 0;
   osvi.wServicePackMinor := 0;
   osvi.wProductType := VER_NT_SERVER;

   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_MAJORVERSION, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_MINORVERSION, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_SERVICEPACKMAJOR, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_SERVICEPACKMINOR, op );
   dwlConditionMask:=VerSetConditionMask( dwlConditionMask, VER_PRODUCT_TYPE, VER_EQUAL );

   Result:=VerifyVersionInfo(osvi,VER_MAJORVERSION OR VER_MINORVERSION OR
      VER_SERVICEPACKMAJOR OR VER_SERVICEPACKMINOR OR VER_PRODUCT_TYPE, dwlConditionMask);
end;

const
WindowsEditionStr : array [boolean] of string = ('Desktop','Server');

begin
  try
    Writeln( Format('Running in Windows %s edition',[WindowsEditionStr[IsWinServer]]));
  except
    on E: Exception do
      Writeln(E.ClassName, ': ', E.Message);
  end;
  readln;
end.

The next code shows how get the parent process filename of a PID, using Delphi.

uses
  Psapi,
  Windows,
  tlhelp32,
  SysUtils;

function GetParentProcessFileName(PID : DWORD): String;
var                               
  HandleSnapShot      : THandle;
  EntryParentProc     : TProcessEntry32;
  HandleParentProc    : THandle;
  ParentPID           : DWORD;
  ParentProcessFound  : Boolean;
  ParentProcPath      : PChar;
begin
  ParentProcessFound := False;
  HandleSnapShot     := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
  GetMem(ParentProcPath, MAX_PATH);
  try
    if HandleSnapShot <> INVALID_HANDLE_VALUE then
    begin
      EntryParentProc.dwSize := SizeOf(EntryParentProc);
      if Process32First(HandleSnapShot, EntryParentProc) then
      begin
        repeat
          if EntryParentProc.th32ProcessID = PID then
          begin
            ParentPID  := EntryParentProc.th32ParentProcessID;
            HandleParentProc  := OpenProcess(PROCESS_QUERY_INFORMATION or PROCESS_VM_READ, False, ParentPID);
            ParentProcessFound:= HandleParentProc <> 0;
            if ParentProcessFound then
            begin
                GetModuleFileNameEx(HandleParentProc, 0, PChar(ParentProcPath), MAX_PATH);
                ParentProcPath := PChar(ParentProcPath);
                CloseHandle(HandleParentProc);
            end;
            break;
          end;
        until not Process32Next(HandleSnapShot, EntryParentProc);
      end;
      CloseHandle(HandleSnapShot);
    end;

    if ParentProcessFound then
      Result := ParentProcPath
    else
      Result := '';
  finally
      FreeMem(ParentProcPath);
  end;
end;

The next code shows how detect If my Delphi application is running under a 64-bit version of Windows.

uses 
  Windows;

    function IsWow64Process: Boolean;
    type
      TIsWow64Process = function( hProcess: Windows.THandle; var Wow64Process: Windows.BOOL): Windows.BOOL; stdcall;
    var
      IsWow64Process: TIsWow64Process;
      Wow64Process  : Windows.BOOL;
    begin
      Result := False;
      IsWow64Process := GetProcAddress(GetModuleHandle(Windows.kernel32), 'IsWow64Process');
      if Assigned(IsWow64Process) then
      begin
        if not IsWow64Process(GetCurrentProcess, Wow64Process) then
        Raise Exception.Create('Invalid handle');
        Result := Wow64Process;
      end;
    end;