If you purchased a Sentinel Super Pro
As of v2.2.13.26, updated October 30, 2009, Sentinel Super Pro H / W Key has been applied to XCom.
For earlier versions of XCom, the Protection Key is not recognized.
You must update your XCom OCX to a version later than October 30, 2009 and install the Sentinel Super Pro driver to ensure normal use of Com.