BAM, Yes you can intall the app on three different machines right away if that's what you want to do, but for a potential fourth install you'll need to explain why to us before a fourth unlock code will be issued. MartinC, The grace period is less than 30 days, i cannot disclose the exact time here, and once it has expired on a specific machine, even if a pirate attempts to re-install that same app, the app will not run without registration and an unlock code. If you have regsitered your first install, you get a new grace period for each subsequent install, covering you for the weekend, should you not be abl;e to unlock via our server. For reference, professional 3d tools such as Max 4, Lightwave, etc, have equally deep security measures, and all are moving to the system we use. I understand your apprehension, but we cannot go forward, with any new software releases, without protection. This system is the best we've found, and we've looked long and hard. Dogface, Do another install on the new hardrive, and just re-register under the grace period.