Perhaps if the user encounters problems he/she may want to test on an installed version.  But I am very satisfied with Firefox Portable and until the latest version of Thunderbird, 78.x, the portable versions I've tried have worked well.  While I don't know this, I think I'd see the same problems with the installed 78.x Thunderbird as with the portable version, but I haven't tested that.  We'll see if others report the problems I found.

There may be portable programs that don't have all the features of installed ones and there may be times when screen-readers don't work well or as well with portable versions.  But I think it’s a good idea to try portable versions and use them, if satisfied.  We all know how accessibility can change from one version of a program to another.  Portable versions allow you to try a new version and retain either the installed version you are using or retain the portable version you are currently using.

Also, another important consideration is that you appear far less likely to have potentially unwanted programs installed when using free software if you use portable programs.  I can't generalize from these instances, but I've seen two instances where the installed version of something tried to install potentially unwanted programs and the portable version didn't.  Considering that many of the installers don't provide accessible ways of informing the user that such programs will be installed unless they are declined, its actually somewhat dangerous to install free programs if portable versions are available and work well.

Gene
-----Original Message----- From: Brian Vogel
Sent: Wednesday, September 16, 2020 9:58 AM
To: main@TechTalk.groups.io
Subject: Re: [TechTalk] Thunder Thinks This Is Spam

On Wed, Sep 16, 2020 at 10:45 AM, Lynette wrote:
this message makes no sense because of your practice of never including info about what you are responding to.-
Agreed.  It came out of nowhere and was apropos of nothing in the context of this topic.

But, back to Thunderbird.  I am going to give the exact opposite advice from Gene.   Portable versions are great things, and I use a lot of them, but if you're using a machine you "always use" and want an e-mail client it is best practice to use the installed version.  There are differences between portable and installed versions of virtually any product that has both.  And when it comes to using screen readers with them, you can be virtually certain that all testing related to the interaction between the two things is going to have used the installed versions of both. You're just adding a layer of uncertainty that seldom has any practical benefit by using a portable version of something that has an installed version.