Thanks for the help, I'm really surprised how such a little detail makes so much difference. I had never ever double clicked an internet file, I had always downloaded them first then run them, or run them from the website. Either way it never worked here, but as soon as I tried the double click method there was a complete change of behaviour. So now I have forge installed, but now another problem, when I try installing a mod, in this case 'little blocks' and place it in the mod folder, minecraft says 'unable to find slimevoid lib file' So I got that and put it into the same folder but still get the same error message. Am I just unlucky first time or is minecraft always so bad?