answer:“apply update” only works when you have an update.zip to apply. You would have had to download that. Doing a factory reset might work, if the problem is in your data or apps. So try it, but don’ expect miracles. Specifically if your phone is unable to finish booting, it can be your radio, or your boot image, or something on that level. Try the reset first. But you may also need to go to the Samsung website and download Kies. That’s their all purpose tool which also lets you load the basic factory firmware. If you can get to the ‘download’ page (not the recovery page) then all is not lost. Question: are you rooted?