Technical
The file is clean according to Jotti. Even avast! now says it's clean.
Here's the problem:
The original file was in the following folder:
C:\Program Files\Common Files\Ahead\AudioPlugins\msa.dll
when I restored if from the chest, ith was put into the following:
C:\Program Files\Common Files\Ahead\AudioPlugins\msa.dll\msa.dll
Since all of these folders are read only, I can't put it back where it should be. Not even in Safe Mode.
For some reason, I can't run the update of Nero unless the file is in the right place as you can see
from the screen captures I previously posted.