procedure RebuildIconCache;

....

const

  sr_WindowMetrics='Control Panel\Desktop\WindowMetrics\';

  sr_ShellIconSize='Shell Icon Size';

function  WindowsDir:string;

var

 buffer: array [..] of char;

begin

 GetWindowsDirectory(@Buffer,SizeOf(buffer));

 Result:=Buffer;

end;

Function UpdateAllWindowsCallback(WHandle : HWnd;

  Var Parm : Pointer) :

  Boolean; stdcall;

begin

 SendMessage(WHandle,WM_SETTINGCHANGE,,);

 Result:=True;

end;

Procedure UpdateAllWindows;

Begin

  EnumWindows(@UpdateAllWindowsCallback,

  WM_SETTINGCHANGE);

End;

function GetIconCacheFile:string;

begin

 Result:=getwindowspath+'ShellIconCache';

end;

procedure DeleteIconCache;

var

 sfile:string;

begin

 sfile:=GetIconCacheFile;

 if fileexists(sfile) then begin

  if deletefile(sfile)=false

  then showmessage('Can not erase file: '+sfile);

 end;

 QueryRestartWindows;

end;

function RefreshActiveDesktop:boolean;

const

  CLSID_ActiveDesktop: TGUID

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

var

  ActiveDesktop: IActiveDesktop;

begin

 try

  ActiveDesktop := CreateComObject(CLSID_ActiveDesktop)

    as IActiveDesktop;

  ActiveDesktop.ApplyChanges(AD_APPLY_ALL or AD_APPLY_FORCE);

  Result:=true;

 except

  Result:=false;

 end;

end;

procedure RefreshDesktop;

var

 wnd:THandle;

 fl:boolean;

begin

 fl:=RefreshActiveDesktop;

 if fl=false then begin

  wnd:=FindWindow('Progman', 'Program Manager');

  if wnd<> then SendMessage(wnd,WM_COMMAND,$A065,)

  else UpdateAllWindows;

 end;

end;

procedure RebuildIconCache;

var

 news,olds:string;

 sz:integer;

begin

 Startwait;

 try

  deletefile(GetIconCacheFile);

  olds:=regreadstring(HKEY_CURRENT_USER,

    sr_WindowMetrics+sr_ShellIconSize);

  sz:=strtointdef(olds,);

  inc(sz);

  news:=inttostr(sz);

  regwritestring(HKEY_CURRENT_USER,

    sr_WindowMetrics+sr_ShellIconSize,news);

  UpdateAllWindows;

  if olds='' then olds:='';

  regwritestring(HKEY_CURRENT_USER,

    sr_WindowMetrics+sr_ShellIconSize,olds);

  UpdateAllWindows;

  RefreshDeskTop;

 finally

  StopWait;

 end;

end;