need to review the authorized computers on my itunes. how to find the list

There isn't a list that you can see. You can individually deauthorise computer's directly on them, but If you have 2 or more computers authorised then you can log into your account on your computer's iTunes (Store > View My Account) and 'deauthorise all' (which you can do once every 12 months) and you can then authorise/reauthorise the computers that you still have and need : authorising and deauthorising.

Thankyou , I will try deauthorizing all. My question is when I deauthoriz

e do I lose all the music I have in my library that I got from those computers?

If I deautorize all computers connected to home sharing ,do I lose all the music I have already gottten from them?

No, not content is removed from the computers, it just means that you won't be able to use iTunes purchases on them until you reauthorise them (which you can do immediate)