Get Default Browser

uses ShellApi

function GetAppName(Doc: string): string;
var
 FN, DN, RES: array[0..255] of char;
begin
 StrPCopy(FN, DOC);
 DN[0] := #0;
 RES[0] := #0;
 FindExecutable(FN, DN, RES);
 Result := StrPas(RES);
end;

function GetTempFile(const Extension: string): string;
var
 Buffer: array[0..MAX_PATH] of char;
 aFile: string;
begin
 GetTempPath(SizeOf(Buffer) - 1, Buffer);
 GetTempFileName(Buffer, 'TMP', 0, Buffer);
 SetString(aFile, Buffer, StrLen(Buffer));
 Result := ChangeFileExt(aFile, Extension);
end;

Beispiel :

procedure TForm1.Button1Click(Sender: TObject);
var
 f: System.Text;
 temp: string;
begin
 // get a unique temporary file name
 temp := GetTempFile('.htm');
 // Create the file
 AssignFile(f, temp);
 rewrite(f);
 closefile(f);
 // Show the path to the browser
 Label1.Caption := (GetAppName(temp));
 Label2.Caption := ExtractFileName((GetAppName(temp)));
 // Finally delete the temporary file
 Erase(f);
end;