1. Download, install and run the BOINC client software.
2. When requested, enter the project's URL. This is the address of the project's web site. If you like, you can copy and paste it from your web browser.
3. When requested, enter your email address and a password of your choosing.
4. BOINC will open a web page that allows you to set other account data, such as name, country, and preferences.

That's it!

Multiple computers under one account

You can run BOINC on several computers under one account. Once you have created an account as above, you can add new computers in either of two ways:

1. Download and install the BOINC client software on each computer, and follow the above procedure.
2. If the new computer is the same type as an existing computer, create a BOINC home directory on the new computer (the BOINC client software resides in a BOINC home directory. If hosts share a network file system, each host must have its own BOINC home directory). Copy the core client executable and all 'account_*' files from the existing computer to the new computer. Do not copy 'client_state.xml'. NOTE: this procedure does not work on Windows because it does not copy registry entries.

Older software versions

The procedure is a little different if you're using a pre-5.0 version of BOINC, or a command-line version of BOINC, or the Mac OS X Menubar version of BOINC. In these cases:

1. Visit the project's web site, click on 'Create account' or similar link, and fill out a web form.
2. You will be sent an email containing an 'account key' (a long random string).
3. Run the BOINC client software. You will be asked for the project's URL and for your account key; copy and paste this from the email you received.