I have 3..20 installed on my windows 11 machine. I have performed every upgrade since, yet when I look at the screen, it says version 3.20. What can I do to fix this?
The newest version of Mp3tag (currently v3.27a) can be installed over whatever previous version exists.
It is important that you install the same type of Mp3tag, as there are
a) 32bit
b) 64bit
c) Portable Version
d) MS Store Version
Please press the menu Help -> About and see what kind of Mp3tag do you have installed for your v3.20
A Portable Version of v3.20 in 32bit would look like this - for example:

It says 32 bit. I want the version to be 64 bit. When I install upgrades they are all 64 bit, and I note there is no change. However, when I try to install a 32 bit version its says I can't install since the version is 64 bit. Is it best to uninstall everything and then install 64 bit from scratch. Is there any other way around this? And if I uninstall, is there a way to do a complete clean uninstall.
Please read this
I suggest to save your configuration first:
Then you can UNinstall all versions of Mp3tag you can find on your windows.
Reboot your Windows.
Then install the newest v3.27a in 64bit in the folder you like.
Then restore the previously backed up configuration into your new folder of Mp3tag.