Thanks to all for the information. Alex - do you have an associated CAB file to re-enable SMS threading? Or would I need to follow the steps provided by Marcus to re-enable?

Attached is the cab file to restore the reg settings

Thanks for the quick reply! Do you have a quick "how to" on editing the registry on the ES400S? I am a WM novice and the rep I am supporting doesn't know how to do this either. Thanks.

cab is attached

I would suggest starting by downloading a remote control software to use with active sync  I use Everywan by Sparus software http://www.sparus-software.com/en/download/software/everywan-remote-sup… 1) Install this on your laptop and connect to the device you want to modify the registry with active sync 2) Start the Evwerywan software and allow it to instal its agent on the mobile computer 3) In the upper left toolbar there is a registry editor..click on it 4) Navigate to the appropriate registry hive 5) Click on the "New Key" icon in the top left toolbar 6) create the new key 7) Click on the New Value icon in the top left toolbar 8) input the new value Once you have the configuration working as you want, do the followin 1) Clean boot and blank the device 2) Use the RemCapture to baseline the devcie 3) Make the changes as described above 4) Use Remcapture to capture the differences 5) Use Remcapture to save the differences 6) Copy the reg file created by remcapture to the /Application directort on a the mobile computer 7) Clean boot the device (not clean boot and blank) You can modify  other devices by copying the reg file created by RemCapture to the appliaction directory and performing a clean boot 3)

Mark, The following key has worked in the past. I have not tried it on the Sprint branded ES400-S: HKEY_CURRENT_USER\Software\Microsoft\Inbox\Settings\OEM
"SMSInboxThreadingDisabled"=dword:00000001   A value of 0 enables SMS threading. A non-zero value disables SMS threading. Remarks This registry key is not present by default. Its absence is interpreted as a 0 value, enabling SMS threading. The reg key needs to be added and set to a non-zero number to turn off threading.