Thank you. This looks much better. Your help is very appreciated.
juce::File file = juce::File::getSpecialLocation(juce::File::invokedExecutableFile).getParentDirectory().getChildFile("CNCUSBController.pdf");
if (file.existsAsFile())
{
juce::Process::openDocument("file:" + file.getFullPathName(), juce::String::empty);
}
else
{
juce::AlertWindow::showMessageBox(juce::AlertWindow::WarningIcon, "Warning", "Help file does not exist!", juce::String::empty, nullptr);
}