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Procedure ChangeWallPaper(FileName:String; Tile:Boolean);
Var
   Reg : TRegIniFile;
Begin
  Reg:= TRegIniFile.Create('Control Panel');
  Reg.WriteString('Desktop', 'Wallpaper', PChar(FileName));
  If Tile then Reg.WriteString('Desktop', 'TileWallpaper', '1')
  Else Reg.WriteString('Desktop', 'TileWallpaper', '0');
  Reg.Free;
  SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, Nil, SPIF_SENDWININICHANGE);
End;

Procedure SetWallPaper(FileName:String);
Begin
  SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, PChar(FileName), 0);
End;