I remembered another pc I have access to on weekends at in-laws,. Software installed fine on that pc. I think previous issue was downloading on a mac resulted in a .exe filename extension.
Problem now is I forgot a charging USB cable as I'd forgotten my Ragnarok won't charge (it never has but I'm in UK and didn't want to have to send it back to USA) I can only use it with a cable plugged in. I have a long cable and controller works fine in MW3 so hasn't bothered me.
I'll have to try again next weekend but in the meantime if anyone has any suggestions about the not charging issue please let me know