If you want to know how to upgrade the client to the latest version, please refer to "CCBoot Client Upgrade Steps" in CCBoot v3.0 Wiki.
It's easy to upgrade and here's the steps -
1) Donwload the latest version from here - http://www.ccboot.com/download.htm.
2) Stop CCBoot service and then uninstall it.
3) Install the latest version into the old install directory.
4) On CCBoot server, double click one client in the client list, click to select the "Keep Write-back File" check box under "Client Properties" in "CCBoot Client" dialog box, then click "No" in the prompt dialog box, then diskless boot this client. Install the latest CCBootClient into the old install directory. Launch CCBootClient and click the "Install CCBootClient" button to install. When finish, shut down this client.
5) On CCBoot server, click "Save to Image" button under "Client Properties" in "CCBoot Client" dialog box of this client.