Peugeot 207 1.6 Hdi starting issues!!

[Craig-o]

My friends 207 1.6 Hdi has died on her. Just made a noise and cut out when she was driving. Now turns over but wont start, and also her windows or anything don't work even though the battery is holding it's charge. Any ideas? The battery terminals are covered in like yellow gunky shit so not sure what that is. Could this be an immobiliser issue possibly? And why would the windows stop working at the same time? Could it be something as simple as a fuse has gone? :blink:

Thanks, Craig