Never again

[theunidada]

I finally got a new pc, in which i'll make sure never to install avast free, or any other iteration thereof.
I pity all users that have avast in a HDD system, as i was one of them. One can easily tell if avast is doing something in the background because my system becomes and stays unusable for entire minutes due to disk activity being completely saturated by avast.
Definition updates? 100% disk usage. Open up the avast GUI? 100% disk usage. Virus found? 100% disk usage. Oh, your system suddenly takes upwards of 6 minutes to go from power button press to desktop idle? Take a guess: https://forum.avast.com/index.php?topic=219756
I play a game called Path of Exile. Every time there's an update to that game, avast will scan PoE's entire 15GB+ database every time. Fun few minutes.
The avast service never starts at startup. You have to open the gui manually and click "restart service" for that to work.

Also check this out. Look for a file called "SWCUEngine.log" in the folder "C:\ProgramData\AVAST Software\Avast\log" and read its contents.
SWCU is actually the "software cleanup" utility. You know what this cute little thing does? Even if the SWCU component in uninstalled, it silently and weekly scans your filesystem anyway for whatever products it finds, writes a summary in that log file and sends the results to the avast servers. I confirmed all this via procmon because i noticed that avast would start scanning random parts of my filesystem followed by a 20KB-sized network request to an avast-related ip without my consent and without showing me a result summary. More on that here: https://forum.avast.com/index.php?topic=214520
I call this a unwarranted user data leak, and has been going on for what... half a decade? i don't know since how long i've been using avast and i've changed systems along the way, losing these log files. I have kept one tho as soon as i realized. This is the oldest summary entry of that log from which i removed some of my info:

[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Initalize SWCU Engine
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Data Directory: C:\ProgramData\AVAST Software\Avast\SWCUData
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] SWCUEngine version: 12.0.0.570
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Product Type: 1
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Product Version: 501348816
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Product Language: [redacted]
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] OS Type: 6.1
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] OS Language: [redacted]
[2017-06-10 10:27:14.128] [info   ] [Engine     ] [ 1488: 1080] Location: [redacted]
[2017-06-10 10:27:56.556] [info   ] [Engine     ] [ 1488: 1080] Requesting Update from Backend...
[2017-06-10 10:27:57.050] [info   ] [Engine     ] [ 1488: 1080] Request successful!
[2017-06-10 10:27:57.067] [info   ] [Engine     ] [ 1488: 1080] We found [redacted] products on your system.
[2017-06-10 10:27:57.070] [info   ] [Engine     ] [ 1488: 1080] Done SWCU Engine
[2017-06-10 10:27:57.070] [info   ] [Engine     ] [ 1488: 1080] ==================================================

[bob3160]

@ theunidada,
Your performance issue isn't Avast it's your lack of HD space.
Fix the HD space problem/issue and you'll solve most of your performance problem.