Studio 1557 FreeFall - Accelerometer, Windows 7 update issue.
I have a Studio 1557 core i7 laptop, which started to exhibit strange behaviour when the laptop was tilted in any direction other than level. When tilted windows (v7 64bit) would automatically switch between menu options and tabs with no user input. After going through a lengthy diagnostics session, I identified an issue with windows update installing the wrong driver for the ST Micro Accelerometer. Windows update identifies the device as an ST Micro ScreenDetection Sensor. If this driver is installed, Dell's FreeFall application (HDD shock protection) no longer functions, and windows goes 'wonky' if the laptop is tilted.
Because the hardware is buried in amongst the Systems Devices section of the device manager, some people may not even know they have an issue.
To confirm if windows update has already installed the wrong driver, you can either :-
a) launch Device manager, expand System Devices and check to see if you have 'ST Micro ScreenDetection Sensor' listed ('ST Micro Accelerometer' is correct).
b) launch control panel, and select FreeFall Data Protection. If the application fails to launch or you get an error, then its likely the wrong driver is installed.
To Fix the issue download the ST Microelectronics Driver (under system utilities) from the dell drivers support site. Running this will remove the existing FreeFall Data Protection application first, and then ask you to re-boot. Once re-booted, install the app again. To check everything is OK, re-do checks a & b above.
To prevent the issue re-occurring or from happening in the first place:
Launch windows update and check for updates, and select optional updates. Select the 'ST Microelectronics - Other Hardware - ST Micro ScreenDetection Sensor Driver' and hide the update. (Windows update info : winqual.microsoft.com/support/?driverid=20312574)