lighting bolt and gear icon

I tried that for my fiances phone and it didn't work exactly right. I held down the volume down, power, and camera button but it wouldn't vibrate until I took my finger off the power button. But I found once it vibrates, still holding the camera button and volume down button, press the power button and hold it until the phone turns back on. It works now.

So lets try this and see if it helps.

Hard Reset using buttons:

Press and hold the Camera + Volume Down + Power until the phone vibrates. Then release the Power key and keep pressing the Camera + Volume Down for a few seconds.

Hello, my phone is a Lumia 925 and its frozen with just the time showing. Nothing else is responding cant switch it off, treid all the volume up down, power and camera buttons with no response. I cant rest coz I cant go in. Any help? The last message I got yesterday was warning me of low memory.

Thanks for the advice, which worked first time! Always a slight panic (for a technophobe!) when things look different!