I updated from 19.2.2374 to the latest version on or about May 26. Shortly thereafter, every few hours my computer would slow to a glacial pace, with the hard drive running continuously, for several minutes. Fortunately, I had made an image backup of the C: drive on May 19 and so on May 30 I restored the computer to the May 19 date. The problem went away. Five days later, on June 4, I once again updated Avast to the latest version. Within a few hours, the problem recurred twice. Once again, I restored the computer to its May 19 state. Since then (3 days ago), I have not had the problem.
While my tests don’t prove that the new version of Avast is the cause of the problem, it certainly indicates that it is: Old version: no problems; update to new version: get problems; revert to old version: problems go away; update to new version: get problems; revert to old version: problems go away.
Between May 26 and May 30, when I first had the problem, I can’t say what updates/installs I’d made in addition to the Avast update. However any such changes would have been removed when I restored the C: drive to its May 19 state. Between May 30 and June 4 I don’t think I made any installs, but in any case they didn’t cause a problem. It was only on June 4 after I again updated Avast that the problem returned, and I know I did not make any other updates/installs on that date. Since June 4 I’ve made other updates/installs, but with no Avast update I’ve had no problem (now for 4 days running).
Are you saying slow pc only occurs immediatly following Avast update (and subsequent restart)?
I am not sure if Avast does some sort of scan after a version update, others may know better , but I suspect it does. If you have a big HD full of files, then scanning that could appear to slow your pc.
As regard coincident updates of Avast and Windows, there is some reports here on furum of that being problematic, e.g. Avast update coinciding with Windows10 update. So if you had a Windows update coincident with Avast update, please let it be known.
No, the computer will perform fine for several hours after the Avast update, then I’ll get the long period of continuous hard-drive access. After letting it finish, or rebooting, things will be fine again for a while, then the problem will recur.
With Windows 7, I have control over when an update is made, and I never do Windows and Avast updates at the same time.
I could do the Avast update a third time to see if once again I get the problem, but I hesitate to do that if it means I might have to do another hard drive restore - I’m always worried that the restore will fail catastrophically.
What is the harm in staying with the old version until Avast releases another update, as long as I keep the definition files up to date?
I’m not aware of any known issue that would manifest this way (in other words, even if this is an Avast problem, I can’t promise it will be fixed in future versions unless we learn what’s actually happening there).
In case you update and experience the problem again, can you please run Process Monitor for a while (something like ten, twenty seconds should be OK), then stop the capture, save the log and upload it somewhere where we can download it? (uploading it to ftp://ftp.avast.com/incoming under a unique name would be OK too)
It’s important that the log is captured at the moment the high disk usage is happening; hopefully that would show us what files are accessed and who is accessing them.
Thanks.