Can Avast update the program automatically if I had checked "never"?

[REDACTED]

The user agreed to the EULA which clearly states that they are allowed to do it.

I don't agree that it's "clearly" stated:

3. Upgrades and Updates
Upgrades and updates of the Software shall be provided to you by AVAST as long as and to the extent in which AVAST in its exclusive discretion makes such upgrades and updates available to the users of the free version of the Software.

They say upgrades will be "provided" and "made available".   Neither implies automatic installation, IMHO.  I (and I'm sure a large percentage of users) felt the "program update" update option could be used to decide if/when to install the provided upgrades. 

If Avast meant that they wanted the option to automatically install program upgrades regardless of the users' program update settings they should have explicitly said so -- both in the EULA and as a warning on the "program update" option screen (IMO).

[davexnet]

As I mentioned earlier, my 2261 upgraded to 2262 even though program update was set to "manual"

I draw two possible conclusions from this.  Either 2261 has a bug and the update type is not honored.
Or 2261 has a serious (undislosed) problem and avast updates it at the earliest opportunity.

I uninstalled and reverted to 2245 and this has been left alone, running without interference for weeks now.

[REDACTED]

I uninstalled and reverted to 2245 and this has been left alone, running without interference for weeks now.

How/where did you get a copy of 2245 to install?  Once my computer went to 2261, I lost my previous version.  It looks like Avast does not create a system restore point before installing a new version of the program.  I didn't know how to go back to something earlier.

[davexnet]

I saved a copy of the offline installer on my flash drive.  I've no idea where to get a copy now...

[bob3160]

I saved a copy of the offline installer on my flash drive.  I've no idea where to get a copy now...

For older versions take a look at the following:

Avast Free: http://www.oldapps.com/avast_antivirus.php#version-listing
Avast IS: https://drive.google.com/open?id=0B-vSic0iJgyeNjF1b29iN1pIZkk