johnd and dalecoy, thank you for the replies.
When I read about the 3 beep on power up I thought "there we go, get a new one."
I have carefully inspected the male and female socket that the logger plugs into and they do not have any bent pins, the logger seats correctly. I have reloaded Weatherlink from the CD on a Win 8.1 box and same problem, real time data displayed, archive data not downloaded.
The manual sums it up -
5.6. Archive download errors
Symptom: Real-time data is passing successfully from logger to computer, but attempts to download archive data are failing, either partially or completely.
Background: Davis loggers can all generate two quite distinct types of data: real-time data (sometimes called Loop data) and archive data.
The manual goes on to say -
5. No solution can be found
If even clearing the logger fails to fix the problem then this could be one of the rare instances where the logger has become faulty.
Before I ordered a new logger I wanted to check with the brains trust on the forum, done that, new logger ordered.