Hi Peter,
Thanks for your prompt response...
The computer I was running the test from was this computer (which does NOT have any ESET products installed). I was simply logged in to the ESS Anti-Theft page in a web-browser, from here. That is, from my employer's computer (I work overseas and the computer in question is at home in Australia, some 2000 km away). That might explain why you couldn't find it.
Anyway, the 'hung' test I started did eventually stop and I logged in from my laptop later on yesterday and was able to grab 2 snap-shots from the affected machine.. So it's all back to normal now. It seems that indeed one must be patient with this. It took not merely several minutes but several hours.
However...
Upon reflection: I think the reason it seemed to hang like it did, is perhaps because the computer which I (remotely) initiated the test to run on, probably would have launched a warning dialog from its ESS, that the test was requested and was waiting... waiting... for someone (normally the person doing the test, who would normally be sitting in front of the computer), to click the 'OK' button on the dialogue?
There was nobody there when the test was initiated. When it worked later in the day, my daughter was sitting in front of it and I guess she would have seen the dialogue and clicked its OK button... I'll find out later if she did indeed see the warning dialogue and click OK...