I don’t think installing 1.3.14, setting “open with” for a format, installing 2.0 then trying to change the association from 1.3.14 to 2.0 would work - the association would stay with 1.3.14. That is certainly the case on Windows XP. The only way I know to get two instances of Audacity in “Open with” is to rename one of the executables.
Gale
@Gale,
That wasn’t what I did. I installed v1.3.14. It installed into “C:Program Files (x86)Audacity 1.3 Beta (Unicode)”. It did the file association itself and correctly. I then installed v2.0 when it became available. It installed into “C:Program Files (x86)Audacity”.It also has done the file association automatically and correctly - which I admit surprised me! The v2.0 file association has over-written the previous file association from v1.3.14. I can now, if I choose to do so, swap the file association to and fro using the “Open With…” technique. All this has taken place on a Win 7 Home Premium SP1 64-bit system.
Audacity does not “do any file associations itself” except for .aup. Your image shows .aup:
Everyone else here is talking about audio files like MP3, WAV…
Choose an audio file for which you don’t have an association with Audacity. Right-click > Open with, browse to either the 1.3.14 or 2.0.0 audacity.exe. Can you set the association to that audacity.exe?
Gale
Ooops! Sorry to have misunderstood the question. 
I can use “Open With…” to set file associations for WAV and MP3 to Audacity 1.3.14 - but not to Audacity 2.0. I then renamed the Audacity EXE file for 1.3.14 to audacity1314.exe, to avoid the conflict of name with the exe for v2.0, and then tried to set file associations for WAV and MP3 to audacity.exe in C:Program Files (x86)Audacity. This failed because Audacity did not appear in the Recommended Programs panel after Browse-ing to it. I then uninstalled Audacity 2.0 and re-installed it to a folder called C:Program Files (x86)Audacity-2-0, thinking that perhaps there were some old registry entries associated with C:Program File (x86)Audacity that were interfering. I was still unable to get Audacity 2.0 to appear in the Recommended Programs panel when doing a file association. In all the above I did NOT re-boot the PC. Should I have done so?
So, to summarize:
I can set file associations for WAV and MP3 files to Audacity v1.3.14 but cannot get Audacity 2.0 to even appear in the list of Recommended Programs. What is different about the way these two versions are installed? Why does a standard Windows process work for one but not for the other?
I’ve joined everybody else; I’m now complaining about this, too! 
There is no need to reboot the computer in any of this. Possibly running CCleaner would help, then start from where that leaves you.
There is no relevant difference in the way 1.3.14 and 2.0.0 are installed. The Audacity version that has the Open with association set first (irrespective whether Audacity is installed or not) will take the association. If you want to associate a file type with a second version of Audacity as well, rename that second version.
Audacity will not appear in the list of “Recommended Programs” for audio file formats unless the installer specifically installs registry keys to do so; however it is the identical names of the application that prevent you associating different versions of Audacity with the same extension.
Gale
Why? I have two versions of PicturesToExe software and both versions appear in “Recommended Programs”. The executable file for this program is the same in both versions. I made no changes to this name during or after the install. Windows 7 happily offers me both v6.5 and v7.0 of PicturesToExe when I do “Open With…”. If Wnsoft (the writers of PicturesToExe) can get it to work, why can’t the Audacity developers. It clearly isn’t rocket science!
We need to make a distinction between file associations with “Audacity Projects” and file associations with “audio files”.
This is how it works on XP:
When Audacity 1.3.x is installed, Windows creates a registry key to identify the Audacity Project (Audacity.Project) and the Audacity Project file extension (.AUP).
.AUP is defined as an Audacity Project (Audacity.Project).
Audacity.Project is given an “OpenWithList” containing “audacity.exe” and has a “shell > open” association with the fully defined path to audacity.exe
Audacity is now the default program for opening .AUP files.
When Audacity is used to open a project by double clicking on the AUP file, Windows registers a key for audacity.exe in the “HKEY_CLASSES_ROOTApplications” section.
The Application entry for audacity.exe contains a “shell > open” entry to the fully defined path to audacity.exe and Audacity will now appear in the list of “Other Programs” that can be associated with audio files.
When Audacity 2.0 is installed, if Audacity 1.3.x has not been uninstalled
The Audacity.Project entry is NOT updated to the new version of Audacity (so Audacity Projects will still open with the 1.3.x version). This allows users to “try out” Audacity 2.0 without altering their previous installation.
The “audacity.exe > shell > open” association also still points to Audacity 1.3.x so Audacity 2.0 does not appear in the list of “Recommended Programs” or “Other Programs”.
Selecting Audacity 2.0 as the program to open a .AUP file with does not work because the registry associates “.aup” files with “Audacity.Projects” and “Audacity.Projects” “audacity.exe” which is still recorded in the registry as the old version. When you browse to the new version and select it, the registry “sees” the program name “audacity.exe” which is already registered, so sees no need to update.
If Audacity 1.3.8 is then uninstalled, the .AUP and Audacity-Project keys are removed, so .AUP files have no file association.
The “audacity.exe” key that Windows created still remains set to Audacity 1.3.x
Re-installing Audacity 2.0 will create new file associations for .AUP and Audacity.Projects.
The Audacity.Project > shell > open entry now points to Audacity 2.0, so Audacity 2.0 is now the default program for opening .AUP files.
However, the “audacity.exe” key that Windows created still remains set to Audacity 1.3.x, which no longer exists, making it difficult to set additional file associations for Audacity 2.0. More about this in my next post.
As it does when you use “Open with” to open an audio file (if that key does not already exist). For that reason, you will get the same issue even if you don’t install Audacity and use Audacity extracted from zips; you won’t be able to associate identically named versions of Audacity with a file type.
Gale
Thanks for the detailed reply, Steve. I’ll wait for the next post before adding further comment.
(Referring only to Windows XP. Apparently Vista/Win 7 are different)
Except that if you don’t, and never have installed Audacity, using “Open With” does not create a permanent file association. The file will open that one time, but to make the file association “stick” Windows tells the user to use “Folder Options control panel”:
By using the Folder Options control panel it IS possible to create multiple file associations from one file type to multiple instances of Audacity with identical file names. However, for this to work the user must work around a bug in Windows and manually enter “%1” after the path to the executable.
Somewhat confusingly there will be a maximum of 2 icons in the “Open with” list - one of which refers to the registry key
audacity.exe > shell > open
and the other (if there is a second icon) refers to the registry key
aup_auto_file > shell > name > command
So that’s why I am seeing two entries for Audacity? I had assumed they were for the two versions that I have installed (on Win 7, of course, in my case). How can I confirm that my two entries do, indeed, relate to the two different Registry entries?
Well that’s the thing, Windows 7 does not have the same options in the “Folder Options control panel” so you couldn’t have done it exactly like this.
How did you set up the file associations?
The file associations with WAV and MP3 have always been done via Open With… Browse to desired program… make sure the “always” box is ticked… and OK everything. They have usually been stolen away from Windows Media Player - although on one previous system I had them associated with VLC prior to associating them with Audacity.
I have no recollection of having to set file associations manually for the .aup files. Nor, as an aside but related to this subject, have I ever had to set file associations manually for the .pte files associated with PicturesToExe software. Indeed, when that software goes through its regular beta programme, the Install Wizard gives the user the option to move the file association to the new beta version. Each beta version and each official version installs into its own folder structure so you can have all beta versions co-existing with all your “official” versions.
I have no idea whether this next info is relevant or not but it seems prudent to declare it so you can build a clearer and more detailed mental picture. Once each week I run Iobit’s Advanced System Care Pro to clean up the PC’s environment. This process includes what Iobit call a “Deep Registry Clean”: how deep and how clean I have no idea. Once each month I run Malwarebytes’ Anti-Malware. The “always on” anti-invasion software is Microsoft Security Essentials. Windows Firewall is the active firewall and the PC sits behind a wireless router providing hardware firewall capability.
I thought you might have meant the case where a file type has no associated program, but testing that on XP here, the association does “stick” for me using “Open with” to set an unzipped version of Audacity to (try to) open a “UVW” file - no versions of Audacity installed, registry wiped of Audacity* keys but not values or data.
To be clear, this is entering the “%1” using the Folder Options > “Advanced” route, and the identical audacity.exe app name is in both application paths? And this is therefore not using the “Open with” dialogue, although you named the context menu items “Open with”?
OK. though that is yet another reason not to use Folder Options 
. Windows Vista/7 just does not have that File Types functionality built in. You have to use a third-party tool like http://defaultprogramseditor.com/ .
@PGA, you can check easily whether different Audacity versions open with each icon in “open with” - look at Help > About Audacity. I suspect, since right-click over the file > Open with only produces one icon, you are opening different Audacity versions. The registry cleaner you use could be relevant if it is completing or adding quotes to give correct syntax.
Gale
Both entries in the “Open With…” list launch the MP3 file into Audacity 2.0. This means that, at present, the registry cleaner is irrelevant? I think this result confirms Steve’s findings: i.e. there are two different Registry keys influencing behaviour of “Open With…” and both are set to use the same version of Audacity.
I was once having a problem with associating an .aup file to audacity 2.0.2.
Before, I was using Audacity 1.3.7 until I had problems recording. I then installed audacity 2.0.2 and uninstalled 1.3.7 but then I could not associate my previous .aup files to the new program so I searched the web and got myself here.
I admit, I did not read everything (there are just too many). But while reading this thread, I thought of installing the 1.3.7 and then I noticed a checkbox to associate .aup and didn’t remember seeing that when I installed the 2.0.2. I finished the installation anyway. Then I uninstalled all of my audacity programs (some 1.3.7 files were not deleted so I deleted the entire folder from the programs folder) and re-installed 2.0.2 and noticed a checkbox to reset all preferences and checked that. Now, all my previous .aup files are associated to the audacity 2.0.2 and I only have one audacity installed in my computer.
wahaha…
i dunno… did this help?
anyways… I’m so happy today.
i hope you all are.
Even if you do what i did, i don’t think you still wouldn’t associate .wav or .mp3 to audacity 2.0.2 cuz i wasn’t able to do that myself. hehe… I always do this step instead: open audacity program, then drag and drop to the program whatever audio file i am trying to edit.
If you want to be able to associate WAV / MP3 files with Audacity, you need to remove the old registry settings. See here for an easy way to do that: https://forum.audacityteam.org/t/file-association-solved/24121/1 (short thread - read all 6 posts.)
The Audacity 2.x installers automatically associate AUP files with Audacity, so no longer offer this as an option.
Gale