Open Windows Device Manager → Expand "Ports (COM & LPT)". If you see "Qualcomm HS-USB QDLoader 9008 (COMx)" , your phone is in EDL mode. If you see anything else, reinstall drivers.
: This lack of a public unbrick tool has made custom ROM development more dangerous, as a software error could require a physical trip to a service center rather than a simple home fix. How to Use MSM Tool (General Process) oneplus 10 pro msm tool
The MSM tool offers different modes:
The (often called the "unbrick tool") is an official, low-level recovery software from OnePlus. Unlike a standard factory reset, the MSM Tool communicates directly with the phone’s processor (Qualcomm Snapdragon 8 Gen 1 in the OnePlus 10 Pro) in Emergency Download Mode (EDL) to flash a full factory image. Open Windows Device Manager → Expand "Ports (COM & LPT)"