Using Older trial version Avast Professional

We had constantly slower system response time and finally it froze up completely while running Avast 7.0 and had to have it stripped out and are now using Avast 4.8 Professional trial version. Now our computer is running fine. I’d like to keep using this version and once the trial runs out, I’ll buy it. Will I need the key from my Avast 7.0? I can’t find it anywhere. Our tech says we can probably get along with using our email address as an identification. Any help on this expensive problem will be greatly appreciated!

the support for 4.8 is running on overtime …

Tic… tac… tic… tac… Plans of supporting were up to December 2012…

hey what os you using?

how much ram you got on the computer?

any other security programs on like a third party firewall?

avast 7 is much lighter on the ram use then 4.8 so.