List all web-browsers installed on a Windows machine

Question

Is there a common method/api to list all web browsers (name, executable, default yes/no) installed on my machine (and per user), and how to find out which is t

Answer 1

That method finds all the browsers that are registered as Start Menu Internet Applications. In practice that will suffice since all the major browsers register themselves in this way. If a browser fails to register itself as a Start Menu Internet Applications then it has no chance of Windows noticing it and offering that browser to the user.

The MSDN topic that explains it all is here: http://msdn.microsoft.com/en-us/library/windows/desktop/dd203067.aspx

The Start menu in Windows XP and Windows Vista contains reserved slots for the default Internet (browser) and E-mail (mail) clients, together commonly known as Start Menu Internet Applications. Applications which register as Start Menu Internet Applications do so across the entire system (per-machine). In Windows Vista, the user may use the Default Programs feature to set a per-user default.

Answer 2

You could do something like

procedure ListRegisteredBrowsers(List: TStrings);
var
  reg: TRegistry;
  ki: TRegKeyInfo;
  i: Integer;
  keyname: string;
  len: DWORD;
begin
  reg := TRegistry.Create;
  try
    reg.RootKey := HKEY_LOCAL_MACHINE;
    if not Reg.KeyExists('\SOFTWARE\Clients\StartMenuInternet') then Exit;
    if not Reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet', false) then
      raise Exception.Create('ListRegisteredBrowsers: Could not open registry key.');
    if not reg.GetKeyInfo(ki) then
      raise Exception.Create('ListRegisteredBrowsers: Could not obtain registry key information.');
    List.Clear;
    SetLength(keyname, len);
    for i := 0 to ki.NumSubKeys - 1 do
    begin
      len := ki.MaxSubKeyLen + 1;
      if RegEnumKeyEx(reg.CurrentKey, i, PChar(keyname), len, nil, nil, nil, nil) <> ERROR_SUCCESS then
        RaiseLastOSError;
      if reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet\' + keyname, false) then
        List.Add(reg.ReadString(''));
      Reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet', true);
    end;
  finally
    reg.Free;
  end;
end;

and

function GetDefaultBrowser: string;
var
  reg: TRegistry;
begin
  result := '';
  reg := TRegistry.Create;
  try
    reg.RootKey := HKEY_CURRENT_USER;
    if Reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet', false) then
      result := reg.ReadString('')
    else
    begin
      reg.RootKey := HKEY_LOCAL_MACHINE;
      if Reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet', false) then
        result := reg.ReadString('')
    end;
    reg.RootKey := HKEY_LOCAL_MACHINE;
    if Reg.OpenKey('\SOFTWARE\Clients\StartMenuInternet\' + result, false) then
      result := reg.ReadString('');
  finally
    reg.Free;
  end;
end;

Test it:

procedure TForm1.Button1Click(Sender: TObject);
var
  sl: TStringList;
  i: Integer;
  DefBrw: string;
begin
  DefBrw := GetDefaultBrowser;
  sl := TStringList.Create;
  try
    ListRegisteredBrowsers(sl);
    Memo1.Lines.BeginUpdate;
    for i := 0 to sl.Count - 1 do
      if SameText(sl[i], DefBrw) then
        Memo1.Lines.Add(sl[i] + ' (Default)')
      else
        Memo1.Lines.Add(sl[i]);
    Memo1.Lines.EndUpdate;
  finally
    sl.Free;
  end;
end;