Ok, so I thought the purge had worked and, temporarily, it did. On the next reboot, though, the same issue re-occurred. I tried another reboot and they came back - but, I'm getting another issue along with it. It seems that on every reboot (maybe not every reboot, but more often than not) I lose the activation - I have to re-activate it by entering my email address and password or licence key. I thought this affected just my main desktop PC, but I'm having the same issues (both the universal apps being empty and the lost activation) on both laptops and my other PC too. It seems weird that nobody else has reported this but it surely can't be just me if I'm having the same issue on all machines I have Start 10 installed on?