When you now start Kopete you will see an empty window.
In the bottom section it says Click here to add an account. Click there or open → to create a new account. We actually want to create a Jabber-account, so we select the menu-item Jabber and click Next. After clicking on Register new account, a new window opens where we can write in a Jabber-server, where the account shall be created.
You can either manually write it into the textbox Jabber server or select it from the provided list, which appears after clicking on the button Choose...
After selecting a server you are able to complete your desired Jabber-ID, i.e. your username. Add your preferred name in front of the “@” in the field Desired Jabber ID. After filling in your password and repeating it you should tick the checkbox Use protocol encryption (SSL) for having an encrypted client-server connection.
Some servers might not be capable of this option, but most of them are. Now click on Register to finish the registration.
Congratulations, you have now registered a new account on a Jabber server!