URI

#include <QApplication>
#include <QSettings>
#include <QDir>

int main(int argc, char *argv[]) {
    QApplication a(argc, argv);

    QString path = QDir::toNativeSeparators(qApp->applicationFilePath());

    QSettings set("HKEY_CURRENT_USER\\Software\\Classes", QSettings::NativeFormat);
    set.beginGroup("YourApp");
    set.setValue("Default", "URL:YourApp Protocol");
    set.setValue("DefaultIcon/Default", path);
    set.setValue("URL Protocol", "");
    set.setValue("shell/open/command/Default", QString("\"%1\"").arg(path) + " \"%1\"");
    set.endGroup();

    return 0;
}