There is multiple ways to check if you have the last update of the version.
CTI for MS-CRM Integration can automatically check for updates at startup. To enable this feature, go to the menu Tools > Options and navigate to the tab Update.
Enable automatic updates by checking the option Automatically check for new update.
To be sure you are using the most recent version of the CTI, go to the menu Help > Check for update. A dialog will ask you to download the last version if you are not using the most recent.