Most are stored in the registry
If you look in the registry for
you will find numbered keys under "appkey"
these are where some of your quicklaunch keys are. (Internet and calc keys should be 7 and 18 respectively.
The mediasmart key is in a different location
you can either change what program launches with those keys or delete the default program associated with each specific key to render it inoperable, the email key cannot be disabled as far as I know. I would back up those registry keys before making any changes.
Source of Information
There is also software to remap the HP quicklaunch keys, not sure how well it works on the G62