Why does Windows list my SSD system drive as removable?

Raymond Chen

Raymond

This has probably happened to you. You right-click the Safely remove hardware and eject media icon, and among the removable devices is your primary hard drive! Surely you can’t eject your primary hard drive. Why is this on the list?

Because the device driver reported that the device was removable.

Explorer doesn’t try to second-guess the device driver. If the device driver says that the drive is removable, then it’s removable.

One of my colleagues reports that whenever he runs into this problem, he installs Intel Rapid Storage Technology, which includes the drivers that fix the problem.

Raymond Chen
Raymond Chen

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8 comments

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  • Avatar
    Ian Boyd

    If your system has AHCI enabled (in the BIOS and the storahci driver runs at system startup), one of the features it provides in hot-swapping of drives. You can unplug a hard-drive’s SATA connector, or plug in a new drive, and it will be recognized and immediately start working. Because the system supports removing and inserting hard drives, the drives are (by definition) removable.

    You can make the drives no longer “removable” by disabling AHCI mode in your BIOS, and returning to regular IDE mode. But then you lose Native Command Queuing (NCQ) functionality.

    It would be nice to another option around the drive’s Removal Policy:

    • Quick Removal: Disables write caching on the device and in Windows, but you disconnect the device safely without using the Safely Remove Hardware notification icon

    • Better performance (default): Enables write caching in Windows, but you must use the Safely Remove Hardware notification icon to disconnect the device safely.

    No removal: Enables write caching in Windows, and you will be unable to choose the device for removal using the Safely Remove Hardware notification icon

    • Avatar
      Ian Kemp

      Wrong. AHCI is a prerequisite for allowing SATA’s hotswap functionality to be exposed; once AHCI is enabled, it is then possible to toggle hotswap for specific port(s) on the storage controller. This may seem like a pedantic distinction, but it’s an important one, because it means that having AHCI enabled does not automatically mean hotwap is enabled.
      The early implementations of AHCI – UEFI and drivers – didn’t make this distinction, thus leading to the situation described by Raymond. Intel’s RST driver is smart enough to recognize that 99% of people don’t actually ever want or need to hotswap SATA devices (and will be confused by prompts that allow them to do so), so it simply claims that all devices on SATA ports aren’t hotswap-capable, regardless of what’s set in the UEFI. However, if you really do need that capability, you can manually eject those devices via Intel’s RST.

  • Avatar
    Thomas McCorkell

    I did once manage to remove the boot drive, way back in the Windows 2000 days. I think I managed this by upgrading the chipset drivers (this would have been on a VIA KT133A/686B motherboard – I was probably trying to fix the delete-my-registry-on-shutdown bug that chipset had) and that happened to remove the IDE controller driver from Windows, as well as all the drives attached to it.
    I was quite surprised at how much of Windows still worked with a missing C: drive – as I recall, even Internet Explorer mostly ran!

    • Brant Gurganus
      Brant Gurganus

      This sounds very similar to when I ran a virtual machine pointed at the host machine’s hard drive. It worked surprisingly well until I tried to reboot the host machine. Massive filesystem corruption. I don’t think I’ve seen a more recent virtualization or emulation tool let you even try that.

  • Avatar
    Jan RingoŇ°

    I have two identical SATA adapters in my poor man’s NAS. One reports drives as removable, the other does not. I did not manage to figure out why. I stopped to bother but still I’m kinda nervous that I’ll click it unintentionally as the drives are in RAID5 (the software one in Windows Server) and take three weeks to resync.

  • Gunnar Dalsnes
    Gunnar Dalsnes

    could it not have been a selection in windows itself? because the user know better than the driver ( how is the driver supposed to know about my workflow, what drives are external or not etc)

  • Avatar
    David Walker

    “You can unplug a hard-drive’s SATA connector, or plug in a new drive, and it will be recognized and immediately start working.”  Well, I doubt anything will be recognized if the drive you unplug is the system (or maybe the boot) drive.  I don’t think Windows would like that.  

  • Avatar
    Fleet Command

    How funny that I must experience this problem a few days after your write about it, on a system that has never had such a problem in the past. Of course, the disk in question is an ordinary HDD, not a SSD.
    And what I did? I replaced a faulty graphic card.