You can sign up to participate in BOINC and download the software here:
There are two ways to sign up:
1. If you had an account in the original SETI@Home Classic project as of 14th May 2004
The folks at Berkeley took a snapshot of all the original SETI@Home accounts on 14th May 2004. If you had an account in the original SETI@Home Classic project as of 14th May 2004 then your account information, including profile and team information, has been transfered to the BOINC project. You now need to activate that account.
You will be asked to enter the e-mail address of your original SETI@Home account. Your new 32 character BOINC account ID will then be e-mailed to that address and you are required to enter it on the activation web page in order to activate your BOINC account. (This is not the same as your original SETI@Home password ID)
If you no longer have access to your e-mail account used to set up your original SETI@Home account then you'll need to set up a new BOINC account
You will then be taken through the settings page (the defaults should be OK for most users) and onto the download page. Download and run the installer for your operating system (Windows, Mac OS/X, Linux or Solaris). When BOINC first runs it will ask for a project URL and an account key. Enter the following to run the SETI@Home project (you can add other projects later):
Project URL: http://setiathome.berkeley.edu
Account Key: this is the 32 character account ID that was just e-mailed to you (keep this somewhere safe).
BOINC will now try to connect to the project entered. Assuming you chose the SETI@Home project URL, it will first automatically download the latest SETI@Home client and launch it. It will then start to download work units and start processing them.
2. If you wish to set up a new BOINC account
You may set up a new BOINC SETI account here. Using this link will create an account that is automatically a member of this team (the Athlonmb.com SETI Team). The rest of the procedure should be similar to that described in (1) except that you will provide a new e-mail address for your new account.