This post will show you how to update every 1 month your eset to get it free for another month. All this practise take from 5-10 mins per month but it will save you a couple of dollars. OK first I need to tell you that this is working for ESET NOD32 Antivirus or ESET Smart Security, also it maybe be working for other ESET products, but I tested only on those two.
So the trials ends in a few days and you see this image:

install the latest ESET NOD ANTIVIRUS 4
After this you need to go and create a free email. Because you need every month different email address. No more then 1 email on a unique email address. I use the service of : http://www.guerrillamail.com/ Once you enter you get a free email.

go to guerrillamail dot com
Once you have the email go to http://www.eset.com/

go to www eset dot com
select downloads from the menu

go to www eset dot com downloads
then choose ESET Smart Security

select ESET Smart Security 4
click on download

enter email and click on download
and fill it with your email address

set the email
after clicking on submit, you will see this message:

another 30 days now
so now we just need to wait to get the email from ESET with the new trial

get email for 20 seconds
and open it and copy paste the trial username and password into the correct fields:

copy rhe username and email
and voilà you have another 30 days for free from ESET. Thank you guys!!!

And voilà you have it for another month