Registry changes not working but Gpo changes working

Hi,

I want to run a script while rebooting the machine. if i have do the chnages in the GPO (COMPUTER CONFIGURATION\WINDOWS SETTING\SCRIPTS(STARTUP\shutdown))  and added the script over there its working fine. if i do the same chanegs under (KLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\State\Machine\Scripts\Shutdown) its not working  , The script is not calling while rebooting the machine.

also when every i do the changes in GPO its update Registry , but if i do any chnages in registry side its not updating GPO.

Can you please any one help me  on this....?

Thanks 

Balaji K