New security software on my work PC today.
One of those disk scrambler things. My old PC had it, but the new one arrived without it installed so I dropped it in to the technicians to have the software added.
When I picked it up, it was working fine. The trouble was, when I got home and restarted the PC, it didn't work.
Similar to the memory stick with built in fingerprint recognition that jams with a software fault every time I try to use it.
At least the banjo and guitar works.
