Noticed, that some Avast! LOG files are locked and can’t be deleted. Why is that? They haven’t always been locked. When i check with ‘Unlocker’ program, it says, that there’s no locking by any file.
I’m using the latest Home version and XP SP2.
You have to temporarily disable the avast self defense module:
- Right click the ‘a’ blue icon on system tray.
- Programs settings > Troubleshooting (tab)
- Disable self defense module
Usually, you can empty the logs from within the Log Viewer.
Thanks a bunch, that worked. 
You’re welcome. But take in account Igor’s suggestion.
You can also limit the log file sizes into the avast Program Settings.
Can you set the limit for LOG files in [i]C:\Program Files\Alwil Software\Avast4\DATA\log[/i] folder? I have set the limit from Avast settings to 1kt, but files in that mentioned folder goes way over that.
What’s that? 1000kb (kbytes)? 1kb (one kbite) is too little…
Sorry, i meant 1Kb. Is it possible to limit the size of LOG files, like setup.log?
Let 100kb at least…
I think Setup.log is ‘out’ of that limit. An avast missing setting as far I know.
I’d mentioned a while back (in another thread somewhere here) that once or twice a month I like to trim back the setup.log to the last couple of weeks or so, so it doesn’t get outrageously big. I agree with Tech that setting a limit to log-file sizes doesn’t seem to apply to setup.log.
In 4.8, I’ve found that to be permitted to save the edited log, not only do I have to temporarily disable self-protection but I also have to temporarily stop on-access protection.