I have tried various things including: (1) uninstall drive and reboot; (2) tweaking in device manager on DMA or PIO mode. (3) Completely unplugging drive and installing from scratch.
For info, on the same IDE cable I have a CD-ROM drive and that is working fine.
I read somewhere that I shouldn't need a specific driver as these are provided by Microsoft. Is this right? Anyway, according to Device Manager, the driver currently assigned to this drive is version 5.1.2535.0, a Microsoft Driver from 1/7/2001 - the same as the driver on my CD-ROM.