Dell Inspiron 14z (N411z) ACPISMO8800 Windows 7 driver [SOLVED!]


Hello Sir/s,
I have faced the same problem after formating the orginal windows 7 64bit operating system in my dell inspiron N 411z model no it ask every time to install SMO8800 driver for your unknown device in device manager please send me this driver to my e mail adddress,thanks from your kind help M M K


That unknown device is a ST Microelectronics DE351DL Motion Sensor. You can get the driver here:

(Dell download link)


Installation Instructions

Hard Drive Installation (via WinZip) with Setup.exe File for R305957.exe


1.Click Download Now, to download the file.
2.When the File Download window appears, click Save (Windows XP
users will click Save) this program to disk and click OK. The Save In:
window appears.
3.From the Save In: field, click the down arrow then click to
select Desktop and click Save. The file will download to your desktop.
4.If the Download Complete window appears, click Close. The file
icon appears on your desktop.


1.Double-click the new icon on the desktop labeled R305957.exe.
2.The Self-Extracting window appears and prompts you to extract or
unzip to C:\DELL\DRIVERS\R305957. Write down this path so the executable (I.e.
Setup.exe) file can be found later.
3.The Self-Extractor window appears.
4.Click OK.
5.After completing the file extraction, if the Self-Extractor
window is still open, close it.
6.Click the Start button and then click Run.
7.Type C:\DELL\DRIVERS\R305957 in the Open textbox and then click OK.
8.Follow the on-screen installation instructions.

More details:

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.

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 (and also the Dell Precision line). You have a nice laptop!

Affected Dell Laptops/Notebooks:

Inspiron N411Z (Inspiron 14z)
(and potentially more if you see an unknown device with Hardware ID ACPISMO8800)

Supported Operating systems:

  • Microsoft Windows 7 32-bit
  • Microsoft Windows 7 64-bit
  • Microsoft Windows Vista 32-bit
  • Microsoft Windows Vista 64-bit
  • Microsoft Windows XP

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…

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

Code 28 on PCI bus

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

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