This article describes that you can do a ...
soft reset in whichever state the phone is, which is in essence a battery pull.
hard reset while turned off, which starts you over without data (so back it up if you go this way).
Other phones probably have their own instructions on doing this; if there is somehow no way at doing this, the only thing left to do ...
The soft reset :
A soft reset can be done very easy on a Windows Phone. You have to hold the on-off switch of the smartphone for a few seconds and then select ” To turn of slide downward” Now the smartphone is turned off and can be switched on again, press the on or off switch.
The hard reset:
If the soft reset does not work you have to run the hardreset ...
I had a similar issue, but after one crash it just showed white screen and nothing more. I did some googling and found out that those devices have an issue with memory card. And i just replaced it with a new one.
On youtube, there are a lot of instructions about disassembling a device: http://www.youtube.com/results?search_query=htc+trophy+memory+card&...
I know some devices, like the htc radar, have an internal battery and you can still do a "battery pull" by pulling down/off the sim card door. There are two contacts on the door that complete the circuit. So, in essense you are doing a battery pull by sliding down the door and breaking the circuit.
A soft reset is equivalent turning the phone (fully) off, and on again, in a asimilar way to removing the battery from phones that had a removable battery. There should be no long term damage from doing this, in the same way there's no risk of damage by switching a traditional PC off by holding the power button for more than 4 seconds.
Micosoft has acknowledged the problem and promised to release a fix soon.
PS: Will update this answer as soon as i get news of the fix.
Try this sequence:
1.Turn off your Lumia device.
2.Press and hold the power button to start your Lumia device.
3.When your Lumia device starts, it displays the Microsoft or Nokia logo. At this instant, release the power button, then press and hold the volume up button. This step should be done quickly.
4.After a few seconds, an image composed of a white ...
Seems like this is a common problem, however, there does not appear to be a (reliable) fix available. Some users have reported clearing the download cache and restarting the download over wifi has helped.