Comment 1 by briang1 (in reply to comment description) on 2014-11-14 10:16
Replying to briang1:

There have been several reports of this problem on the freelists list. it only seems to affect Windows 7 and later.

Myself I cannot get Avast to install from the latest archive due to inaccessible installer, so cannot check, but thought it wise to at least raise this ticket in case it is an nvda bug.

There is a log file on the list and also a comment that taking the machine back to before the last Avast update makes it work and that it seems to be quarantining a file that might well be important.

I know no more than this myself, for as I say, i cannot test it.

If I can still find the relevent messages I'll add them here.

From:
Ron Canazzi aa2vm@roadrunner.com
I ran JAWS, went to the Virus Chest under
Avast, and there listed as number 8 BIG AS LIFE, was a DLL file which
was associated with c:\program
Files (x86)\NVDA. It was quarantined on 11/06/2014 at 4:45 PM EST. This
time stamp is precisely 15 minutes before I noticed the issue with NVDA!
I restored and excluded it and after 2 prompts as to whether I was
really sure I wanted to do this, I was able to restore and with it full
functionality for NVDA.

For those of you attempting this, be sure to choose the restore and
exclude button. Otherwise,
Avast will quarantine it again.

Comment 2 by briang1 on 2014-11-14 13:17
I wonder, is there a way to exclude Avas's false positive from command line?
Now the problem should be corrected, the file blocked with Avas was:

"C:\Program Files (x86)\NVDA\lib\VBufBackend_gecko_ia2.dll"

Of course if avast has now corrected it, it might be OK, however the self protect mode of avast and the more recent apparent inability to use the installer might need somebody to take these issues up with the Avast developers, perhaps, as this issue could have been sorted far more easily, if the interface had been accessible to nvda by default.

As far as I am aware, there is no way to fix false positives with antivirus's. Closing
The accessibility of the interface of Avast is covered in #3241. It would be recommended to contact the developers of Avast and ask them to improve accessibility into their app.

This was probably due to the av blocking in proc injection (If that's possible even).