How can I install an older version of PS without removing the current one?

[Scott_BFAR]

In past I have on some computers had more than one copy of PS. I think even now on a couple I have more than one version. After installing 26.8.0, I've found some annoying bugs. I want to install an older version but not remove the current one. This will allow me to do some comparative testing. 

But now I get a message that the previous version will be removed. This didn't used to be the case. How can I install more than one version of PS on my comptuer?

[gener7 · Accepted solution]

If you have "Auto Update" in your Creative Cloud app turned on, you would want to uncheck "older versions" under Advanced options.

[D Fosse · Accepted solution]

You can install an older version, but unless you do it in the right order it will take over file associations and be the one that opens by default. The last installer activity will always claim file associations.

So you want to do it in this sequence:

1. uninstall the current version
2. install the old version
3. reinstall the current version

If you later want to uninstall the old version, the same applies. So to avoid breaking file associations altogether, do it this way:

1. uninstall the current version
2. uninstall the old version
3. reinstall the current version

Always keep "remove older versions" unchecked to avoid problems with file associations. Manage versions manually, as above, instead.