Since Microsoft changed driver signing requirements after Windows 7, the M810 (designed originally for XP/Vista/7) requires a specific installation method.
: For specific safety and SCBA-related RFID applications, the 3M Software Portal provides utility applications for programming cards and downloading data logs. 3m M810 Rfid Reader Driver Download
To best help you, I'll clarify:
Ensure another device isn't "camping" on the reader's assigned port. USB Power Management: 3m M810 Rfid Reader Driver Download
Because the M810 is a legacy device (original drivers date back to 2007), many users find drivers on technical databases. Sites like Treexy and DriverIdentifier host the 3mbus.inf files required for Windows 10 and 11. Technical Specifications 3M Software Download Portal 3m M810 Rfid Reader Driver Download