They were 3 1/2". I haven't seen one for years, there were also the Amstrad CD2 ones that were 3.0" (I had the 4 1/2" ones made especially for me!).
I looked at the task manager, the computer has huge excess capacity, Z370 AORUS Ultra Gaming 2.0 Mobo, i7-8700K CPU, 16gb RAM, NVIDIA GeFOrce GTX 1070. Plus SSD's for drives C:, E:, F:.

A couple of weeks ago I refreshed the whole system and have only loaded essential programs - so XAR should be rattling around quite freely.

When will there be a fix? I was suprised that this current post seems to have just petered out without a hard fix.

Many thank for your help, will press on with FileZilla.

Martin