You will have to change the setting in your registry. I don't know of another way to do it.
1) Start - Run - type "regedit"
2) Look in "HKEY_LOCAL_MACHINE\SOFTWARE\Adobe\Lightroom\1.0\Adobe Photo Downloader\Preferences"
3) Double-click the item called "AutoLaunchOnDeviceConnect".
4) Change "Value data:" from '0' to '1'. Click OK.
5) Close regedit, and try connecting your devices now.
How do I turn off the lightroom auto program start?
When I plug in a USB key or turn on my USB external hard drive to get a file or photo to move, Lightroom starts as soon as I click on the photo.
If I shut down the program, then everything works as expected. Eg I click on a photo on the key and my associated viewer opens it.
Under preferences in the program, I have checked off "when a USB card is detected" ---"Do Nothing" but I think the program needs to be running for that to work.
I have checked my file associations and my files are linked to my viewer and not Lightroom.
Where to now?