Is it *really* necessary to turn off A/V programs when installing/uninstalling Acad?
Instructions say to do so, but turning off my avast is not clear, so I searched for instructions and I come across avast forums where everybody says that is "old thinking" and is no longer necessary as it used to be.
The answser is YES, as you can see the recommend at the end of this solution. Since there are so many anti-virus applications and different configuration, maybe someone will install successfully without disable his anti-virus application, but we can not guarantee this will works for you.
Disable any virus-checking software running on your system. Virus-checking applications may block certain activities detected as suspicious, e.g., accessing the registry or adding/removing/updating DLL files, even though these activities are common when installing or removing programs. Not only can it slow down the installation process, but it can actually introduce corruption. So make sure that your virus checking software is turned off before you install, and make sure you turn it back on when you're complete