A hard reset is a hardware function and doesn't require the operating system to load.
First, have you tried a soft reset? Pushing the stylus into the small hole on the bottom of the phone.
Have you tried removing the battery?
this sometimes works to get things running again.
Be aware that if you do a hard reset all your data and programs will be lost.
It will be as it was when you took it out of the box when you first got it.
So, to quote the user manual that is available online,
To perform a hard reset using device keys
1. Press and hold the left SOFT KEY and the right SOFT KEY, and at the
same time, use the stylus to press the RESET button at the bottom of
2. Release the stylus, but continue pressing the two SOFT KEYs until you
see the following message on the screen:
This operation will delete
all your personal data,
and reset all settings to
the manufacturer default
settings. Press SEND to
defaults, or press any
other button to cancel.
3. Release the two SOFT KEYs, and then press the button on your
Warning! Your device will be set back to factory default settings. Please ensure any
additional installed programs and/or user data have been backed up before
a hard reset is performed.
I would also suggest removing any SD cards you have.
If a hard reset doesn't work then you know you have a hardware problem that require you to get the phone replaced.