Regrettably, my problems are of my own making. With the intention of converting some video tapes to DVD (and I have done this before successfully), I plugged the Grabber into the USB without remembering that since the last time I had done this, I had reformatted my trusty 'puter. And of course, the programme (Movavi Video Editor 8 SE) couldn't see the Grabber. Eventually I realised I had a disc with some software on it associated with it, and set about (belated) installing the software (? drivers), and found that it would only partially complete the task, but have been unsuccessful in installing it completely (there were three files, I think, 2 labelled USB2861, and another one - only one USB2861 installed along with the other, whose name I have forgotten), so continue not to be able to see the Grabber in the above programme. In other words, only one of two USB2861 files installed.
So far, I have uninstalled the driver (using some info I found on the net), rebooted my machine, attempted to reinstall the software - but all to no avail.
So - what next? Pretty please!