I am running lightroom 4. How can I find the preference to prevent it from automatically loading when at startup and looking for photos to download?
Check that you haven't somehow placed Lightroom in the system's Startup folder (it doesn't do it automatically).
More likely, however, is that you have a drive or other device which connects on startup and the autoplay settings trigger Lightroom to launch the Import process.....this is the same as when I insert a memory card into a card reader, this causes Lightroom to launch.
There are a couple of settings you could look at:
1. On the General Tab of the LR Preferences (Edit menu>Preferences) there is the option to "Show Import Dialog when a memory card is detected". If you have this checked, then this could be causing the problem. Unchecking that option would likely fix it, but then you'd lose the option to have LR start when you did insert a memory card.
2. Have a look at your system Autoplay settings (Start>Control Panel>Autoplay)....see what you have listed that will automatically launch Lightroom. Here's my settings, and you'll see that only Media content type "Pictures" will lauch LR. However, I used to also have "Mixed Content" set the same, but that caused LR to start if I connected an external drive.....so I changed it to "Take no Action". You may need to do something similar.
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