To upgrade your trial version of ESET NOD32 Antivirus 4 for Linux Desktop to the full version, follow the steps below:
Open the main program window by clicking the ESET icon in the notification area, or by clicking Applications → System Tools → ESET NOD32 Antivirus 4.
Click Update Username and Password setup.
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Type the new username and password that were sent to you upon purchase of your license. The following are EXAMPLES only:
If you entered your ESET-issued Username and Password correctly, you will be upgraded to the full version and the detection engine update will complete successfully.