can't update

[JeanneMarie]

Every time I try to update MultiCommander, the process fails. The heart of it seems to be:
Failed to replace C:\Program Files\MultiCommander (x64)\MultiCommander.exe due to error 5...

I see an old thread that talks about running as administrator, but don't see how to do that.

I see the instructions at https://multicommander.com/docs/Upgrading 
regarding updating from the installation folder. 
I ran MultiUpdate.exe from C:\Program Files\MultiCommander (x64)
Am I looking in the right place?
MultiCommander was not running and isn't in the system tray.
Here's that transcript, which seems to cite the same error:

Updating Multi Commander Located in : "C:\Program Files\MultiCommander (x64)"
=============================================================
You are running on a 64 bit platform.
==================================================
Make sure you do not already have Multi Commander running.
==================================================
Press start to begin update process.

Checking if newer version exists.
Version information received.
Current installed version is 15.8.0.3135
==> Newer version found.
Downloading update for Multi Commander...
Downloaded completed...
Unpacking Multi Commander Update...
Updating Multi Commander...
Updating to version 16.2.0.3213
Failed to replace C:\Program Files\MultiCommander (x64)\MultiCommander.exe due to error 5...
Update script error at line 22 (COPY=%UPDATE%\MultiCommander.exe,%INSTALL%\MultiCommander.exe)
Update FAILED.

What am I missing here? Do I have to simply re-install?
Thanks for any advice,
Jeanne
(using Windows 11pro, ver. 10.0.26200)

[Mathias (Author)]

Something is blocking MultiUpdate from replacing the file. saying that is access denied when trying to overwrite the file (error 5 is windows error code for access denied )
If you installed into Program files. then MultiUpdate should request to start update process as admin. if it does not, then make sure you starts as admin.

Do you still get same error.. then something is blocking MultiUpdate from replacing the file.  it can be special security software that you might have that have extra protection for files in program files or something.
Anyway the error is that Windows does not allow for the file to be overwritten