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windowswinapidrive-letterdeviceiocontrol

Converting a drive letter to a Partition ID / Disk ID

Given a drive letter, how do I get the OSImage InstallTo Partition ID and Disk ID without using the registry?

Solution

  • The WMI class Win32_DiskPartition is what I need. Now to figure out how to use WMI to get this information from a drive letter.

    Win32_LogicalDisk is also useful, MSDN Example, and this stackoverflow answer.

    Update: Hmm, this doesn't work! Not in the Windows Installer anyway (WMI is missing from Windows PE!!) so I am using the other answer QueryDosDevice (e.g. \\.\PhysicalDisk1\Partition0) and hacking it together. This sucks Microsoft, accept a damn path in your installer.

    Answer: IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS works to get the Disk ID. And DeviceIoControl IOCTL_DISK_GET_PARTITION_INFO_EX (thanks TLama) gets me the Partition ID.