ACPI\SMO8810 Dell driver [SOLVED!]

Q. Hi, I just bought a Dell laptop and resinstalled Windows 7 on it. Now I have an unknown device ‘ACPI/SMO8810’. What driver can I download to fix it?

A.Here is the download link to solve your ACPI/SMO8810 Unknown Device issue:

mirror, Dell dl link

NOTE: That is the accelerometer that is built into your laptop.

More details about free fall sensors:

That free-fall sensor is an accelerometer which can detect movement (i.e. downward acceleration or falling) and using that sensor your laptop can take steps to protect itself by parking the hard drive heads or other measure.

NOTE: The driver is specifically for your Dell laptop’s ST Microelectronics Free Fall Sensor that shows up as Unknown Device ACPI\SMO8810 :-)

Screenshot showing the unknown device:

The SMO8810 unknown device listing as shown in Device Manager and the properties page

The driver installation process:

It is very easy to install and only takes a few clicks once you have downloaded the correct driver   :-)

Device manager properties page after the correct driver has been installed:

Device manager showing the SMO8810 device after the correct driver has been installed!

IBM pioneered this technology in their ThinkPad line way back in 2003 and Dell has implemented it as well. Of course, it has applications beyond protection as even the Apple iPad/iPad 2/iPhones have an accelerometer which developers can use for games and other purposes!

PS I would like to thank you for your question, as I am a bit fan of the Latitude E series. You have a nice laptop!

Dell Laptops/Notebooks that use ACPI\SMO8810:

Precision M4700
Precision M6700
Latitude E6430 ATG
Latitude E6530
Latitude E5430
Latitude E6430
Latitude E6330
Latitude E6430s
Latitude E5530
Latitude E6230
(and others withs Hardware ID ACPISMO8800)

Dell Vostro 3360 and Dell Vostro 3460 (see this link)

Supported Operating systems (OS):

Windows Vista 64-bit – Home Basic
Windows 8 32-bit – H
Windows XP – Home Edition
Windows 8 64-bit – EM
Windows Vista 64-bit – Ultimate
Windows 7 32-bit – Home Premium
Windows Vista 64-bit – Home Premium
Windows XP x64 – Professional Client
Windows 7 64-bit – Professional
Windows XP – Professional
Windows 7 32-bit – Home Basic
Windows Vista 32-bit – Ultimate
Windows 7 32-bit – Starter
Windows XP – Tablet PC Edition
Windows 7 32-bit – Professional
Windows 8 32-bit – Pro
Windows Vista 32-bit – Starter
Windows Vista 32-bit – Home Basic
Windows Vista 32-bit – Home Premium
Windows Vista 64-bit – Business
Windows 8 64-bit – H
Windows 8 64-bit – Pro
Windows Vista 32-bit – Business
Windows 7 64-bit – Home Premium
Windows 7 64-bit – Home Basic
Windows 8 32-bit – EM
Windows 7 64-bit – Ultimate
Windows 7 32-bit – Ultimate

More info on this topic:

IBM Research | People | Mark A. Smith | APS

IBM Research | People | Mark A. Smith | APS of these systems use accelerometers placed on the motherboard to detect motion. A kernel software driver interfaces with the accelerometer and exposes its acceleration…

Accelerometer - Wikipedia, the free encyclopedia

Accelerometer – Wikipedia, the free encyclopedia accelerometer is a device that measures proper acceleration. This is not necessarily the same as the coordinate acceleration (change of velocity of the device in space), but…
Free-fall sensor – Wikipedia, the free encyclopedia page was last modified on 3 January 2011 at 13:52. Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. See Terms of use…

Code 28 on PCI bus

Driver functionality rated 5/5 stars (no problems and simple install)
[starreview tpl=16]

UPDATE from Kanika:

The driver worked just like you said and now our Dell Precision laptops are perfectly configured. Thank you!



  • dann

    was looking for acpi/smo8810 for a clean windows 8 install on my dell you driver link did the trick,, thank you!!

  • Tim

    Thank you, that was exactly what I needed! I only like to download what is apparently required. I try not to download and install everything on the DELL drivers page for any given workstation/laptop. This was a great thread. Thank you

    • Hi Tim,
      Thank you for your nice comment. It is definitely nice install only what is required for a nice fast machine and leave all the bloatware off :-) I am very glad this thread was helpful to you and I hope you enjoy your nicely configured Dell laptop!

      Best regards,

  • Dan Evans

    This worked a treat. Almost wasted half a day day on Dell’s website trying to track it down. Great guide, well explained and fantastic information.

  • aTTA

    This did the job for E5530 Dell

    • Hi,
      Thank you for your nice comment. I am glad the driver worked well on your E5530.

      You have a very nice laptop, the E5530 is one of my favorite Dell laptop models and I use one a lot for work :-)

      Best regards,

  • Propellerhuvud

    Like aTTA said, it really did the job for my E5530! :-)
    Reinstall messed up my drivers, but now it’s all working. Using Win8.1 and so far, most hair is still on head 😉

    • Hi Propellerhuvud,
      Thank you for your nice comment. I am really glad the drivers are working well on your E5530 :-) Also, hope you are enjoying Windows 8.1 as I find it to be a nice upgrade from Win8!

      Have a great week,

    • Hi Propellerhuvud,
      Thank you for your comment and the confirmation that everything is working well on Windows 8.1

      Have a great week and enjoy your nice E5530!

      PS which LCD do you have on your E5530? I used one with the 1920×1080 display and found it be VERY nice! :-)

      • Propellerhuvud

        Hi JD,
        I have the 1920×1080 size for screen. It’s great to fit so much content on it, but being nearly 50 y/o getting focus on that high resolution isn’t all that easy. Still great value for money! :-)

        Enjoy your week too!

  • roger

    very very great, my issue has been solved.

    thanks a lot!

  • If someone has the problem that cannot instal this driver I can help you. Just send me a email. I say it cause i had problems installing the driver but ot was because i had my windows updates off… the instalation shows me an error.. david.comyepiz.t AT

  • reueld

    worked like a charm on Dell Latitude E6330.
    thank you!

    • Hi reueld,
      Thank you for the nice comment, I am very glad to hear that the driver works well on the E6330. :-)

      I have used the E6430 and E5530 before but never the E6630… I love that your model has a very compact size yet keeps the full docking capabilities etc. That is a very cool laptop that you have!

      Question: how do you like the screen on the E6630?

      Best regards and have a great week,

  • CW

    Thanks JD, very helpful. As you know unfortunately even with the service tag, Dell cannot tell you a whole lot of what you need and don’t. Your tip helped!

    • Thank you for your comment CW. You are totally right, the service tag is helpful but not perfect for finding exactly what is needed! I am very glad my page helped :-)

      Have a great week and thanks again!

  • Jan

    I am you most grateful. :-)

  • tony

    thanks for this article, this resolved my unknown device problem.

  • Norm

    I just completed downgrading Windows 8 to Windows 7 on a Dell M4800. Thank you for pointing me in the right direction. “Unknown Device” resolved.

    • Hi Norm,
      Glad to hear your switch to Windows 7 has gone well and that my page was useful :-)

      How are you liking your M4800? They look like nice machines!

      Best regards,

  • James Godwin

    Also resolved my ‘unknown device’ issue. Thanks for putting me on the right path!

    I found the following driver to work for my Latitude E5440 running Windows 8.1

    ST Microelectronics Free Fall Data Protection

  • John Suit

    Thanks! Surprisingly this is still affecting the latest Dell laptops. They all have the ST Free Fall Sensor installed, even if they come pre-configured with an SSD. Worthless sensor to a large portion of laptops today, but annoying to have that yellow exclamation staring at you from the device manager. The worst part is that even though this driver is branded as an ST product, its vendor code (Properties of device -> Details -> Siblings) still shows as 8086, which is Intel’s VEN number.

    • Hi John,
      Thank you for your comment and for the info on the VEN number. It is certainly crazy that the free fall sensor is still in play after all these years, especially with the prevalence of SSDs (as you mentioned).

      Which Dell(s) are you using?

      I have been enjoying a few Dell’s lately:
      Dell M6700 at work (love the screen and multi-drive capabilities)
      Dell Inspiron 11 2-in-1 for home/kids (terrible trackpad, no backlit keyboard, but otherwise a great inexpensive machine)
      Dell E5450 for travel, work at home (love this machine, wish it had dual SSD capability… the E5440 could apparently do both msata and SATA)

      All of those laptops are utilizing SSDs and I hope to never go back to HDDs again 😉

      Thanks again for commenting John and have a great Labor Day weekend!

      Best regards,


    Really, thank you verry much!

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