Placed it on two PCs and had to take it off after a week. the two new Pcs were constantly occupied by the software, although we restricted its scanning schedule. the interruption to the daily work of the Pcs was so much that we took it off and bought another antivirus software that worked perfectly. if Kaspersky is too much for a new Intel i7 processor based pc, I cannot imagine how slower pcs will deal with it.
I love this flash. I have it now for few months and I can't see much difference between it and the originals of Nikon. for the price value, I highly recommend it. I have the SB600 and this one is so much better.