QSettings can't read some of HKLM registry entry

I have installed the SDCC toolchain v3.9.0 (64-bit installer) to the "Program Files" folder, and want to read the registry entries in:

"HKEY_LOCAL_MACHINE\SOFTWARE\SDCC"

path (e.g to read an installed path, version and so on). But, the QSettings returns an empty strings., e.g. this code:

#include <QCoreApplication>
#include <QSettings>
#include <QDebug>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    static const char kRegistryNode[] = "HKEY_LOCAL_MACHINE\\SOFTWARE\\SDCC";
    QSettings registry(QLatin1String(kRegistryNode), QSettings::NativeFormat);
    QString rootPath = registry.value(QStringLiteral("Default")).toString();
    qDebug() << rootPath;
    return a.exec();
}

returns the 'rootPath' as empty string.

I don't know, what is reason (maybe the access rights?), but if I open the Regedit (trough Win + R) and then I see there all entries (please see screenshoot).