var Wallpaper : string;

{©Drkb v.3(2007): www.drkb.ru}

begin

 Wallpaper := 'C:\windows\ACD Wallpaper.bmp';

 SystemParametersInfo (SPI_SETDESKWALLPAPER, 0, PChar(Wallpaper), SPIF_SENDCHANGE)

end;

program wallpapr;

uses Registry, WinProcs;

procedure SetWallpaper(sWallpaperBMPPath:String;bTile:boolean);

var

 reg : TRegIniFile;

begin

// Изменяем ключи реестра

// HKEY_CURRENT_USER

// Control Panel\Desktop

// TileWallpaper (REG_SZ)

// Wallpaper (REG_SZ)

 reg := TRegIniFile.Create('Control Panel\Desktop' );

 with reg do begin

  WriteString( '', 'Wallpaper',

  sWallpaperBMPPath );

  if( bTile )then

  begin

  WriteString('', 'TileWallpaper', '1' );

  end else begin

  WriteString('', 'TileWallpaper', '0' );

  end;

 end;

 reg.Free;

// Оповещаем всех о том, что мы

// изменили системные настройки

SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, Nil,

 {Эта строка - продолжение предыдущей}SPIF_SENDWININICHANGE );

end;

 // пример установки WallPaper по центру рабочего стола

 SetWallpaper('c:\winnt\winnt.bmp', False );

//Эту строчку надо написать где-то в программе.

var
 Reg: TRegIniFile;
begin
 Reg := TRegIniFile.Create('Control Panel');
 Reg.WriteString('desktop', 'Wallpaper', 'c:\windows\mybmp.bmp');
 Reg.WriteString('desktop', 'TileWallpaper', '1');
 Reg.Free;
 SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, nil, SPIF_SENDWININICHANGE);
end

uses

 ComObj, ShlObj;

procedure ChangeActiveWallpaper;

const

 CLSID_ActiveDesktop: TGUID = '{75048700-EF1F-11D0-9888-006097DEACF9}';

var

 ActiveDesktop: IActiveDesktop;

begin

 ActiveDesktop := CreateComObject(CLSID_ActiveDesktop)

  as IActiveDesktop;

 ActiveDesktop.SetWallpaper('c:\windows\forest.bmp', 0);

 ActiveDesktop.ApplyChanges(AD_APPLY_ALL or AD_APPLY_FORCE);

end;

unit Walpaper;
interface
uses
{$IFDEF WIN32}Windows, Registry, {$ELSE}WinTypes, WinProcs, IniFiles, {$ENDIF}
 Classes, Controls, SysUtils;
type
 TWallPaper = class(TComponent)
 private
  PC: array[0..$FF] of Char;
{$IFDEF WIN32}
  Reg: TRegistry;
{$ELSE}
  Reg: TIniFile;
  WinIniPath: string;
{$ENDIF}
  function GetWallpaper: string;
  procedure SetWallpaper(Value: string);
  function GetTile: Boolean;
  procedure SetTile(Value: Boolean);
  function GetStretch: Boolean;
  procedure SetStretch(Value: Boolean);
 protected
{$IFNDEF WIN32}
  constructor Create(aOwner: TComponent); override;
{$ENDIF}
 public
 published
  property Wallpaper: string read GetWallpaper write SetWallpaper;
  property Tile: Boolean read GetTile write SetTile;
  property Stretch: Boolean read GetStretch write SetStretch;
 end;
procedure Register;
implementation
{$IFNDEF WIN32}
constructor TWallpaper.Create(aOwner: TComponent);
begin
 inherited Create(aOwner);
 GetWindowsDirectory(PC, $FF);
 WinIniPath := StrPas(PC) + '\WIN.INI';
end;
{$ENDIF}
function TWallpaper.GetWallpaper: string;
begin
{$IFDEF WIN32}
 Reg := TRegistry.Create;
 Reg.RootKey := HKEY_CURRENT_USER;
 Reg.OpenKey('\Control Panel\desktop\', False);
 Result := Reg.ReadString('Wallpaper');
 Reg.Free;
{$ELSE}
 Reg := TIniFile.Create(WinIniPath);
 Result := Reg.ReadString('Desktop', 'Wallpaper', '');
 Reg.Free;
{$ENDIF}
end;
procedure TWallpaper.SetWallpaper(Value: string);
begin
 if not (csDesigning in ComponentState) and
  not (csLoading in ComponentState) and
  not (csReading in ComponentState) then
 begin
  StrPCopy(PC, Value);
  SystemParametersInfo(spi_SetDeskWallpaper, 0, @PC, spif_UpdateIniFile);
 end;
end;
function TWallpaper.GetTile: Boolean;
begin
{$IFDEF WIN32}
 Reg := TRegistry.Create;
 Reg.RootKey := HKEY_CURRENT_USER;
 Reg.OpenKey('\Control Panel\desktop\', False);
 Result := Boolean(StrToInt(Reg.ReadString('TileWallpaper')));
 Reg.Free;
{$ELSE}
 Reg := TIniFile.Create(WinIniPath);
 Result := Reg.ReadBool('Desktop', 'TileWallpaper', False);
 Reg.Free;
{$ENDIF}
end;
procedure TWallpaper.SetTile(Value: Boolean);
begin
 if not (csDesigning in ComponentState) and
  not (csLoading in ComponentState) and
  not (csReading in ComponentState) then
 begin
{$IFDEF WIN32}
  Reg := TRegistry.Create;
  Reg.RootKey := HKEY_CURRENT_USER;
  Reg.OpenKey('\Control Panel\desktop\', False);
  Reg.WriteString('TileWallpaper', IntToStr(Integer(Value)));
  Reg.Free;
{$ELSE}
  Reg := TIniFile.Create(WinIniPath);
  Reg.WriteBool('Desktop', 'TileWallpaper', Value);
  Reg.Free;
{$ENDIF}
  SetWallpaper(Wallpaper);
 end;
end;
function TWallpaper.GetStretch: Boolean;
var
 i: Integer;
begin
{$IFDEF WIN32}
 Reg := TRegistry.Create;
 try
  Reg.RootKey := HKEY_CURRENT_USER;
  Reg.OpenKey('\Control Panel\desktop\', False);
  i := StrToInt(Reg.ReadString('WallpaperStyle'));
 except
 end;
 Reg.Free;
{$ELSE}
 Reg := TIniFile.Create(WinIniPath);
 i := Reg.ReadInteger('Desktop', 'WallpaperStyle', 0);
 Reg.Free;
{$ENDIF}
 Result := i = 2;
end;
procedure TWallpaper.SetStretch(Value: Boolean);
var
 v: Integer;
begin
 if not (csDesigning in ComponentState) and
  not (csLoading in ComponentState) and
  not (csReading in ComponentState) then
 begin
  if Value then
  v := 2
  else
  v := 0;
{$IFDEF WIN32}
  Reg := TRegistry.Create;
  Reg.RootKey := HKEY_CURRENT_USER;
  Reg.OpenKey('\Control Panel\desktop\', False);
  Reg.WriteString('WallpaperStyle', IntToStr(v));
  Reg.Free;
{$ELSE}
  Reg := TIniFile.Create(WinIniPath);
  Reg.WriteInteger('Desktop', 'WallpaperStyle', v);
  Reg.Free;
{$ENDIF}
  SetWallpaper(Wallpaper);
 end;
end;
procedure Register;
begin
 RegisterComponents('JohnUtilend;'
end.

program change;
uses
 windows;
var
 s: string;
begin
 s := paramStr(1);
 SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, @S[1],
  SPIF_UPDATEINIFILE OR SPIF_SENDWININICHANGE);
end.
// Запускаешь:
// change.exe "имя файла с картинкой"