Disk usage 100% while auto updates are off

[Ivan.N]

Hello!
Avast often loads a hard disk for a long time by 100%. Automatic updates and streaming updates are disabled. PC became unusable - at startup it can freeze for about 20 minutes. Why can it happen? How can it be fixed? I've been using Avast for many years; it has never happened before. Even auto-update has never been disabled - I had to do it quite recently, but it didn't help. There is no problem with the disk itself.

[Asyn]

- Which Avast..? (Free/Premium)
- Which version/build of Avast..?
- OS..? (32/64 Bit..? - which SP/Build..?)
- Other security related software installed..?
- Which AV(s) did you use before Avast..?

[Ivan.N]

Avast Free antivirus 20.7.2425 (build 20.7.5568.600)
OS Windows 10 x 64,    Version 10.0.18362 Build 18362
No other antiviruses, only Windows built-in software.
I have been using Avast since Windows installation for more than 5 years.

[Asyn]

1. Download Avast Free Antivirus: https://files.avast.com/iavs9x/avast_free_antivirus_setup_offline.exe
2. Follow instructions: https://www.avast.com/uninstall-utility (Run this tool for all prior installed Avast versions..!!)
3. Reinstall Avast with the downloaded installer from point 1.
4. Reboot.

[Ivan.N]

I did everything as you said. But Avast still continues to use the disk 100% for 5-10 minutes after each power up. In the Task Manager I see "Avast Tools" utility which reads something from the disk (1.3 MB/s) and also writes, but less (up to 400 KB/s).
Auto updates and streaming updates are turned off.
Now Avast version is 20.8.2432 (build 20.8.5684.602).

[Asyn]

Hi, if you're willing to help, see: https://forum.avast.com/index.php?topic=237567.0