One of the readers, Norm asked, “Do you know where I can find the tweak to enable the camera flash even at low battery levels?” That’s a good question. By default, HTC HD2 camera flash is disabled when battery level drop below 20%. You cannot use camera flash on either photo or video mode. So how to enable HTC HD2 camera flash on low battery?
By changing the registry will do the trick.
HKEY_LOCAL_MACHINE\Drivers\BuiltIn\Battery\
- FlashLightPowerUnavailable value from 1 to 0
Just in case you need it. Here is the link to Free Windows Mobile Registry Editor. Note – this is not a permanent solution. You need to change the registry again after you soft reset your phone. 
via: xda-developers
Windows Mobile 6.5 does not have registry editor built in. Therefore, I need to install registry editor myself. After searching around Google and xda-developers, I found a free Windows Mobile registry editor called ~ PHM Registry Editor. It is an old application but does it job well.
PHM Registry Editor
