Repetitions of alert message

Twenty-four hours ago,  NIS 21.4.0.13 flagged three items on an external drive for quarantine on my Windows 7 x64 Home Premium Sp1.  The actions taken were 'removed'.  Subsequently, I have had three tray alert messages of the same flagging.  The flagging was not part of any scheduled or intentional scan, merely the accessing of the drive.  The drive itself has been acting 'strangely' very recently and continues to do so.  The labelled disk drive is renamed 'Microsoft Office Click-to-Run 2010 (Protected)'.

 

Any ideas?