IPAQ Windows 2003se screen saver

I have a HP IPAQ hx4700 with Windows 2003se as the OS and I want to use this as a GPS / MP3 player on my motorcycle with the 12 volt power attached to it all the time to keep it running. The problem I am having is when I use the GPS software by it self the screen saver / power saver does not effect it and it stays off so I can see the maps and hear the directions so I can follow them.
Now when I start the Windows Media Player it will go into standby after X number of minutes and I can't see the maps. This happens even if I minimize the Media Player and have the map application on top. What I am looking for is the reg hack to disable all the screen saver / power saver options so when I have it plugged in to a power outlet be it a 12 volt or wall outlet they will not turn on or activate. Anyone have any idea where to look for these settings, I have done all the ones that the OS will let you do but it still goes into standby.
Thanks.