I am totally amazed at how simple and effective this software is. My mac for the first time in 2 yr's. would not boot. I was bummed out to say the least. First I tried all the apple tricks to no avail. I considered a reinstall but had never done one so I was hesistant, then I remembered I bought and installed Superduper. I have an external LaCie drive with a copy of my internal drive on it. I just opt booted to the external started Superduper and told it to copy to my internal drive. In 20 min's it was finished and auto restarted to my internal drive. Walla, I thank ya Superduper...I'm a believer now! George