I've used both the paid and free versions and appreciate PRTG very much! I recommend it often. I have come to realize that my installations are never very "stable" in the sense that I go away for a couple of months and when I return, it just isn't working. The port number has changed from 8011 to 80 ?? and I have to remember what to do to fix that or look it up again. My logins don't seem to work and I have to redo those. My system configuration changes and I can no longer see the system devices that I need to see. What can I do to keep things intact?? This is a very big deal as I need it to be working when I need to look at failures, etc.