procedure TForm1.FormCreate(Sender: TObject); var i: integer; OldErrorMode: Word; OldDirectory: string; begin OldErrorMode := SetErrorMode(SEM_NOOPENFILEERRORBOX); GetDir(0, OldDirectory); i := 0; while i <= DriveComboBox1.Items.Count - 1 do begin {$I-} ChDir(DriveComboBox1.Items[i][1] + ':'); {$I+} if IoResult 0 then DriveComboBox1.Items.Delete(i) else inc(i); end; ChDir(OldDirectory); SetErrorMode(OldErrorMode); end;