Can a License key be used on multiple conputers

If I have multiple computers that I am using on a home net work do I need to register each copy and get a key for each one or one I have one key can I just use that on each computer?

I use the same avast key on each of the systems on my home LAN.

So if I understands this correctly,I’ve got 3 comps in my home and I can install Avast Pro on the 3 of them with the same license??They’re all wired in the same router. ???

Avast Professional is licensed per computer.
If you have three computers, you need three licenses. Doesn’t matter if they are all on the same LAN.

http://www.avast.com/eng/how-to-buy-avast-professional-edition.html

Thanks for making the difference clear … I should have stated in my post that the same license key on the systems is for the avast Home edition.

I just thought I read the license info wrong!Thanks for clearing that up. ;D

I thought the same key could be used for all of the computers but I wanted to make sure.

Never mind… welcome to forums.