No personal information or information about your computer configuration are transferred. There is a one-way hash* of some machine configuration data, your chosen password, and the optional email address sent to the server. Your application may have an optional registration page and if you choose to fill that out, that information is also transferred during the first activation. If you do not provide the optional information (email address and registration information) then no personal information will be transferred. We suggest you do not use one of your important personal passwords for the activation password, or a password that personally identifies you.
*One-way Hash: Codes that identify parts of the computer are put through a special function (called a 'one way hash') that turns the codes into one code number that is unique to your computer but cannot be deciphered (or reverse engineered) to determine what those components are. Only this hash value is sent to the activation server and not the details on the computer parts.