While Investment Account Manager 3 (IAM3) is able to download updates to itself, it needs to be exited for an update to be installed, to avoid installation failing when replacing open files.
Once IAM3 has been exited, look in the IAM3 program group for an icon labeled "Update IAM3 Individual" and double-click on it. This will unzip and install the update and will then display the "readme.txt" file describing the changes in the update.
While the above method seems to work reliably, there is also an icon labeled "Update IAM3 Installed to Program Files", which does the same job, but does not display the readme.txt file at the end.
A third alternative and reliable update method is to double-click the "Run Command...", browse to
c:\Investment Account Manager 3 Individual\UPDATES\IND3UPDATE.EXE
Then click "Run". When the WinZip Self-Extractor open, click "Unzip". The number of updated files is displayed at the end of the update process, and then the readme.txt file is displayed.
It should perhaps be mentioned that running "IAM3 Utilities" provides an "Update Program" utility, but this fails when trying to overwrite iam3_utility.exe.
The above methods have been tested within CrossOver 21.2.0 under Fedora 35 Linux, but similar results would be expected under other Linux variants and MacOS.