Why my PC pop out Windows Explorer error message at random times?

[RonSilverback]

"Evidence" that AVAST is at fault

Hi,

I'm late on this topic. I started having the NTDLL.DLL problem late in July, and only recently did I suspect that it was due to Avast. In my case, the error pops up every time I close Outlook, and it also occurs sporadically when Windows Explorer is used. Note that even when I experience the problem, scanning my system shows no bad files in Windows.

So, this morning I uninstalled Avast completely, shut down my PC, rebooted a few times, and ran with no ant-virus for a while. The error did not occur at all, no matter how many times I opened and closed Outlook.

Next I reinstalled Avast Premium Security from scratch. As soon as I booted after Avast was installed, I got the NTDLL.DLL error from Windows Explorer. And, yes, every time I close Outlook it shows up again.

As the file within Windows is still healthy (i.e., when I uninstalled Avast, all was good), I have to assume that Avast is using a corrupted copy of the NTLDLL.DLL -- or that it intentionally uses a newer version that is OK for Win 10 and Win 11, but does not work on Win 7. The good news is that Win 7 has not been corrupted. The less good news is that I have to find a replacement for Avast.

Grrrrrrr