Problems with the PC this morning on updating Windows and installing the new version of Avast, meant PC would start but nothing would run. Did a system restore in safe mode which at the moment has left the pc without an anti virus (it is not connected to the internet) set WD back to version 60, easy enough to correct.
When I started WD the data logger downloaded everything that it had, which would have been OK except that it missed an hour of data, which was around the time the PC was off. But this data would have been held on the data logger which wasn’t switched off. Only an hour I know, but why would the data logger lose an hour?