I wanted to reset all data and settings on my iPhone, so I went to the Settings >> General >> Reset Data function within the iPhone to do so, thinking that all would be fine. After I did that, my iPhone showed a moving progress bar for a long while, but then displayed the Apple logo when it was completed, and froze at that screen.

I tried giving it a reset by holding down both the power and home buttons, but that did not work. So I had to restore my iPhone in the end — here’s what I did:

1. Launch iTunes
2. Connect your iPhone to your computer
3. Turn off your iPhone (by holding down both the POWER and HOME buttons)
4. Turn on the iPhone while holding down to the HOME button
5. CONTINUE TO HOLD the HOME button until the phone enters Recovery mode
6. Restore your iPhone with iTunes. This will reinstall the OS.

That solved my iPhone problem for me, and brought my iPhone back to life.