Garmin Express 7.23 windows 11 won't find nuvi 1450

Are you using a laptop or desktop?

Longshot but reboot PC and open Device Manager. Expand list under Universal Serial Bus Controller.  Double-click each entry and click its Power Management tab, if it has one. Uncheck the box "Allow PC to turn off...". Repeat for all USB entries.  Reboot and retest.

Tried resetting USB Power Management; no joy.  Now the nuvi 1450 locks up the computer when plugged into the usb port.  All other apps freeze; apps resume when the nuvi 1450 is unplugged.

Weird, does the device work OK while powered in a car in the normal manner?

Yes

I know you said you are using different ports and cable but if the device works properly in the car, then to me that point to a PC problem or a cable problem.  Make sure you aren't using any type of a USB hub, plug directly into the port.  If you haven't already test the rear ports which should consist of the following.  It won't hurt to test the port with Smart Power On but that of course might introduce a wrinkle to the puzzle.  As much as it might be a pain, reboot the PC between each of the port tests. 

(2) USB 2.0 ports with Smart Power On

(2) USB 3.2 Gen 1 ports

(1) USB 3.2 Gen 2x2 Type-C port

If you need guidance on which port is which, a user manual can be found at 8960 setup and specifications.  Specifically see page 11 & 12.

Attempted to access the nuvi 1450 plugged into the USB Smart Power On port.  No Joy.  Garmin Express did not find the nuvi 1450.  

I then attempted to access my son's Drive 52 plugged into the same usb port.  Success.  Garmin Express found it.  I was able to add maps to the Drive 52 using MapInstall.exe that I had previously downloaded to the xps8960.

Strange!  And thanks for your time & effort.

This leads me to believe that there is corrupted software on the nuvi 1450. Agree?  If so, can I do a "factory reset" on the nuvi 1450?

Sounds like it might be corruot.  If you want to do a factory reset go to https://support.garmin.com/en-US/?faq=foz6Qhall58hiKV5JDpVf9.  Although a slightly different topic the rest instructions are the same.  Note you will lose “all user data”,  That will be mainly stuff like favorites