Free v4.40 of HD Sentinel Pro up for grabs atm.
Installation and unlock instructionsLink
After submitting the form, you'll get an e-mail with the download link of this special version. Just install it and there is no need to manually specify registration name, unlock code or similar: all functions and features are available immediately after installation.
The Hard Disk Sentinel Professional package you will receive allows the use of all functions, options and features of Hard Disk Sentinel Professional version, and can be used until 31 Dec 2015. If updated to newer versions (for example by the automatic update from File menu) then it will switch back to unregistered version.
As this version is older than the current latest, the support of newer devices (hard disks, SSDs, RAID controllers, Windows versions may not be complete and accurate. If you prefer to have the latest possible updated versions (with a lifetime license with lifetime free updates and complete support), consider ordering Hard Disk Sentinel Professional lifetime license with 40% discount. This offer is available until 27 October 2014 only.
Mini review by IainB here
Forgot to say this came by way of OzBargain