I have an older Zeus13 AIO FC, and I can't for the life of me get it to be recognized by either Windows, or Betaflight - In Device Manager I keep getting a 'Device Descriptor Request Failed' whenever I plug this FC in - I have tried installing the latest STM drivers (v1.5.0), Zadig, and Impulse Driver Fixer, to no avail - All my other FCs are recognized right away, so I am wondering if somehow this board got fried - I get the normal LEDs when plugged in (If I hold the bootloader button while plugging it in I still get the same error) - At this point I suppose I am looking for an 'outside-the-box' solution, so if anyone has any ideas, I would be eternally grateful!

Have you tried a different computer? If not then that is worth a try.

Do you have an Android device? If you do, try connecting the FC to that using an OTG cable and see if the SpeedyBee app is able to detect and connect to the FC.

If you have access to Linux , try that. If it doesn't work on that or Android, it's probably not going to work at all.

I will also suggest taking a magnifying glass and using a toothpick move the legs on the usb connector on the board to ensure they are securely soldered. Very little pressure just to ensure the usb port has a solid connection to the board.

If you have an ST-Link device then you can try and see if you can read the MCU. On the underside there should be 10 programming pads in the form of 5 pairs of DATA and CLOCK pads. 4 of these pairs of pads will be for the MCU’s of the 4 ESCs. You one pair will be for the FC MCU. This might be an overkill to some people but its not that hard to do.

I am able to connect to the FC using my Android tablet and SpeedyBee app, but cannot flash firmware in SpeedyBee - I used the same OTG cable from my PC to connect to my Android, so I'm pretty sure the cable was not the issue

UPDATE:
For some reason after connecting to my Android, then re-connecting to my PC the flight controller is now recognized, and I was able to flash BF v4.3