I'm sorry for the inconvenience. I tested this on a Windows 8.1 (64bit) PC. I saw the same problem, but was able to resolve it following way: -I installed Sentinel HASP/LDK Windows GUI Run-time Installer (Windows, 13.3 MB, Version 6.60, Released 2013-08-08) from the page: http://sentinelcustomer.safenet-inc.com/sentineldownloads/ -However the dongle was still not detected so I rebooted the PC. After the restart the Licence manager reported multiple dongles detected. -I uninstalled Sentinel driver from add/remove programs. Re-inserted the Dongle and it started to work for me. I hope this will work better for you. Kind regards, Marko