What is the difference between jedwed-, jeglich- and jed-? In my dictionary all three mean 'any'. And in what context are they used? Are they interchangeable?
OK, I'll try a more general reply:
jeder, jede, jedes = every. This is the normal word to use.
jeglicher, jegliche, jegliches = any, somewhat higher register and (slightly?) dated, quite often used in the negative: Der Sprecher enthielt sich jeglichen Kommentars. Jegliche Hilfe kam zu spät. The "no exceptions whatsoever" aspect is highlighted. Can be safely replaced by "alle" or "jeder/-r/-s", as a rule.
jedweder, jedwede, jedwedes: ~ "each and every". Very stilted, might be used in contracts and such, certainly not in everyday conversation. Learners of German probably should stay clear.