This has happened to me once before and it’s really frustrating. I’ve tried to renew my home version of Avast at least 4 times now and I’ve never been sent a new registration number. Now it’s expired and I’m unprotected!
What do I do?
Are you using a free email account?
Are you using any antispam application?
Can you go to the SSL page version and register from there: https://secure.avast.com/scripts/register.php?lang=ENG
See the tutorial: http://www.avast.com/files/tutorials/insert_key.htm
Please take a look here: http://www.avast.com/eng/i_was_successfully_r.html
I’m not using free email and I don’t believe I have any antispam software. Last time this happened we went through all this and you just emailed me the number and that finally worked. I have no clue what the problem is and I’m not exactly a geek when it comes to this stuff. 
You aren’t unprotected, things will work as normal, just that you can’t get any VPS updates so you need to resolve this quickly. Hopefully the suggestions given by Tech will help.
Have you tried registering with a different email account from a different domain ?
Having re-read your previous Topic about this could it be that this is the same problem with cannacare.org dns
Do you not have your old regstration key as based on the original Topic date you should have a long time left before you need to re-register your home license June 2007 ish.
I lost a hard drive and had to reload everything…including Avast (I am a true Windows hater at this point). I don’t know much about a DNS, but it I suppose that could be it…but I’m clueless about how to fix it. I do have the old registration key I believe. Would that work again?
Yes, I believe it would work again right up until the original expiry date.