i think the problem has something to do with 3 computers hooked up on the same internet.
in the "help", i came up with this:
If avast! does not accept the key, you probably typed it incorrectly (again, we recommend that you use the copy & paste method), or the license does not match (e.g. the license key for a workstation cannot be entered in avast! installed on a server operating system). In such a case, contact the vendor of the avast! program or ALWIL Software support.
i registered, copy&paste the registration key into the box, then it tells me the key is invalid.
this is my first time downloading/registering.
much thanks for the help, ill check back soon.