The problem goes from Avast 9 to 17 : i have the same problem and just installed avast 17 on a factory system image from 2013 with an offline VPS update (28/08/2021).
The first version which should be ok (as far as my tests go on win7 SP1) is avast 19.
By the way, edialchu, avast 19 is available on filepuma (search on google : "site:filepuma.com avast 19") and you can install it. Only some recent avast21 versions ask for a win7 update.
The real problem is :
- yes we could upgrade to win7SP2 or even win10
- yes we could upgrade to avast19 or even avast21
But in my long experience, there is no update (OS or software) which makes things lighter. And i tried avast 19, 20, 21 : they're all heavier than avast 9 (surpriiiiise). Moreover, avast9 is more customisable.
Everyone does not own a powerful PC, nor does want/afford one.
My PC is a 2013 netbook, which was already considered as "weak" at the time.
My weak PC is functional and i refuse to throw it away or make it kneel because of "forced" updates. Reasons : money, environment, principles.
Our problem is triggered by a VPS update, because at least three users around the world had the same problem the same day. We are not asking complete maintenance on old avast versions.
I'm pretty sure there's just one single virus definition which poses a problem between two consecutive days.