How to list physical disks?

#WMIC wmic is a very complete tool

wmic diskdrive list

provide a (too much) detailed list, for instance

for less info

wmic diskdrive list brief 

#C Sebastian Godelet mentions in the comments:

In C:

system("wmic diskdrive list");

As commented, you can also call the WinAPI, but... as shown in "How to obtain data from WMI using a C Application?", this is quite complex (and generally done with C++, not C).

#PowerShell Or with PowerShell:

Get-WmiObject Win32_DiskDrive

Update Feb. 2022, Microsoft announces in "Windows 10 features we're no longer developing"

The WMIC tool is deprecated in Windows 10, version 21H1 and the 21H1 General Availability Channel release of Windows Server.

This tool is superseded by Windows PowerShell for WMI.

Note: This deprecation only applies to the command-line management tool. WMI itself is not affected.

I've modified an open-source program called "dskwipe" in order to pull this disk information out of it. Dskwipe is written in C, and you can pull this function out of it. The binary and source are available here: dskwipe 0.3 has been released

The returned information will look something like this:

Device Name                         Size Type      Partition Type
------------------------------ --------- --------- --------------------
\\.\PhysicalDrive0               40.0 GB Fixed
\\.\PhysicalDrive1               80.0 GB Fixed
\Device\Harddisk0\Partition0     40.0 GB Fixed
\Device\Harddisk0\Partition1     40.0 GB Fixed     NTFS
\Device\Harddisk1\Partition0     80.0 GB Fixed
\Device\Harddisk1\Partition1     80.0 GB Fixed     NTFS
\\.\C:                           80.0 GB Fixed     NTFS
\\.\D:                            2.1 GB Fixed     FAT32
\\.\E:                           40.0 GB Fixed     NTFS

GetLogicalDrives() enumerates all mounted disk partitions, not physical drives.

You can enumerate the drive letters with (or without) GetLogicalDrives, then call QueryDosDevice() to find out which physical drive the letter is mapped to.

Alternatively, you can decode the information in the registry at HKEY_LOCAL_MACHINE\SYSTEM\MountedDevices. The binary data encodings there are not obvious, however. If you have a copy of Russinovich and Solomon's book Microsoft Windows Internals, this registry hive is discussed in Chapter 10.

If you only need to look at the existing disks, this one will suffice:

powershell "get-physicaldisk"

I just ran across this in my RSS Reader today. I've got a cleaner solution for you. This example is in Delphi, but can very easily be converted to C/C++ (It's all Win32).

Query all value names from the following registry location: HKLM\SYSTEM\MountedDevices

One by one, pass them into the following function and you will be returned the device name. Pretty clean and simple! I found this code on a blog here.

function VolumeNameToDeviceName(const VolName: String): String;
var
  s: String;
  TargetPath: Array[0..MAX_PATH] of WideChar;
  bSucceeded: Boolean;
begin
  Result := ”;
  // VolumeName has a format like this: \\?\Volume{c4ee0265-bada-11dd-9cd5-806e6f6e6963}\
  // We need to strip this to Volume{c4ee0265-bada-11dd-9cd5-806e6f6e6963}
  s :=  Copy(VolName, 5, Length(VolName) - 5);

  bSucceeded := QueryDosDeviceW(PWideChar(WideString(s)), TargetPath, MAX_PATH) <> 0;
  if bSucceeded then
  begin
    Result := TargetPath;
  end
  else begin
    // raise exception
  end;

end;