Running and hurting ham strings!?

I am desperate to start to learn to run. It has taken me a couple of years to get my breathing and asthma sorted out. Every time I try and start to run, my hamstring and chins kill me. I have tried taking co-codamol beforehand and it doesn't work. I have also tried running for 1 minute and then walking for 1 minute but after 5/10 minutes of interval running, I cant stand the pain. Has any one got any tips.