audyauser2012: the pendrive system protection as I understand is very sensible. prrbably you have 1 or more file corrupted, then when you insert pen it auto block and now never can use. it like you have changed the harddrive (ok you not it but is the same). the only solution is to reset the pen. I had the similar problem of you because I make a 2. disk backup and cannot install. I kontact ketron italy send pen to them and return reset for free in about 3 days, cost 1.60 €