Safenet has recently upgraded the driver for the Sentinel hardkey. This has resolved some issues with Windows recognizing the key under certain circumstances, in particular later versions of Windows. The Sentinel hardkey is the black key with green lighted tip, available for the full version of IWS versions 6.1sp2 and above.
The driver can be found by clicking the following link: SafeNet
Select the Sentinel Driver v7.5.8 and install, rebooting if prompted.