Months ago, I had bought the Avast! Internet Security 1 year 3 users, and I only used to install on 2 computers, which means that I only used up 2 subscription(Is that correct?).
I wonder if the last subscription can I used to use to renew my Avast! antivirus next year when the license is overdue?
Kindly answer my question! Thanks for taking time to read this.
P.S. Sorry for my Bad English 
[non-important] i think the incoming server is being weird thats the third thread tripling tonight. (at least night where i am. and where ht server is lol.)
Unfortunately the start date for the licenses was from the date of purchase so at the end of that period all licenses in the multi system license will expire.
You could try using the on-line contact form, http://www.avast.com/contact-form.php?loadStyles to contact Sales inquiries and explain the situation and see if they can offer anything outside of what is the normal proceedure.
Thks! 
You’re welcome - hopefully they can work something out.