How does iit work????????????

I am having problems with my sansa express with it not wanting to charge from an AC adaptor, and i found out that updating the firmware will help, so i downloaded the firmware updater and tried to run it but it just says “sansa updater can only be launched by sansa service!” I am confused. How do I update the firmware for my express when the prog will not launch. Do I have to download stuff off the internet for it?. It would help if SanDisk provided a manual with with it too