Until recently I had no problem with 18.8.2356, but in past few days had problem with avastui.exe process rising to 50% of CPU with scvhost.exe taking the remaining 50%. Not a lot of CPU to do anything else.
My experience is posted here:
https://forum.avast.com/index.php?topic=220639.msg1549868#msg1549868So far I have done:
1) Repair of Avast. -No improvement.
2) Uninstall (using avastclear) and reinstall. -No improvement.
3) Uninstall (using avastclear) again, search and delete all traces of avast on the machine.
Reinstall Avast.
Stopped Microsoft Update (valid still for MSOffice updates, not WinXP)
Only after that has CPU calmed down a bit. AvastUI does peak for a a few mins but dies back afterwards no sustained thrashing as before.
I am now wondering if an earlier version of Avast is better suited to WinXP than 18.8.2356. I can't remember the reason DavidR gave for rolling back to an earlier version. That was some months back. Comments welcome.
Whilst I kept a copy of 18.8.2356 installers, I didn't keep any earlier versions, so advice where a stable earlier version can be downloaded could help.