I'd not been looking forward to week 2 because my knees were sore (but then they always are, and I don't think it's much to do with the running), but I decided to give it a go.
So everything started fairly well, and by the end of the second 90 sec run my knees seemed easier, but then during the third 90 secs, my legs turned to lead. I finished the run by walking briskly and after a 20 minute rest I now feel OK.
I reckon there's nothing for it but to repeat week 1, and then try again with week 2 run 1.
Such is life ...