I was talking to a friend last night, about Skyrim, and I asked him how much damage do your bows do and he said 200 to 300! So I was like holy crap, my bows only do 43 to 70. He then told me that he has the highest level of smithing as well as enchanting and that's how he increases the damage of his bows. What I want to know is, can you increase the damage of a normal bow by smithing, without enchantments, if so, what is the process like?

Thanks for any advice or tips or help. G

if you're not messing with enchantments you just temper the bow at a grindstone.
you won't get anywhere near 200-300 without enchantments(or potions) though.

Is he on the PC?

How did he get damage that high? Enchantment abuse.