Physical disk. What is the logical disk?

First, specify the guid and use setupdigetclassdevs to obtain information about all devices in the harddisk and volume categories.
Define_guid/
(Harddisk_guid, 0x53f56307, 0xb6bf, 0x11d0, 0x94, 0xf2, 0x00, 0xa0, 0xc9, 0x1e, 0xfb, 0x8b );
Define_guid/
Volume_guid, 0x53f5630d, 0xb6bf, 0x11d0, 0x94, 0xf2, 0x00, 0xa0, 0xc9, 0x1e, 0xfb, 0x8b );

Hdevinfoset = setupdigetclassdevsw (lpguid, null, null, digcf_present | digcf_interfacedevice );

Then, setupdienumdeviceinterfaces is used to enumerate the interface information of each device in the device information set.
If the call succeeds, call setupdigetdeviceinterfacedetail to obtain the details of each device.
Then, use cm_get_parent and cm_get_device_id to obtain the device instance id of the device instance, which is a string similar to the following: pciide/idechannel/4 & e3ec092 & 0 & 0, USB/vid_0d7d & pid_0150/4d3b424303c0.
You must have noticed that all USB devices start with USB and contain both the PID and vid of the device. In this way, you can determine whether the device is from a specific manufacturer. Next, we need to get the drive letter corresponding to the USB device. Because each device may contain multiple volumes, we can use a similar method to obtain information about all volumes, by comparing the device number, you can determine whether multiple volumes belong to the same device. Then, you can use the physical device name of the volume device to reverse query the symbol (querydosdevice) to obtain the drive letter corresponding to the volume, we can further obtain the drive letter of all volumes on a physical disk.