Well, I've graduated - in a sort of round about way. I got to week 7 and was doing the 25 min runs and just kept going an extra 2-3 mins during each one, eventually dropping the formal program and working my way up to my original goal to complete the 5k between my house and work.
That was about 5 weeks ago - It's been a struggle maintain running the entire 5k three times a week - as often or not I peeter out at about 3.5 and walk the rest, but I'm steadily improving and managed to complete 7th 5k this morning in under 40mins for the first time. (why they named this programme c25k I don't know - I can't even -sprint- at 6min/km, let alone jog comfortably over 30mins at that pace).
Still, being 45 and 105kg, I'm delighted that I can manage to jog at 8min/km continuously for 40mins at all.
Have realised that the running shoes I brought when I started are beginning to wear down and am wondering what to do next. Part of the route to work is shared with the local park-run which I think I may try when I'm a bit lighter and a bit faster (and my left knee a bit less dodgy) - but that's got a nasty set of steps in it, so that'll be some time before I do that.
Meanwhile, I'll keep pounding on.