Today during the IOS upgradation of GSR, we come to face across the different problem, In this we cannot enter into the config mode. When ever we tried we got the one message that is “Config Mode Lock”. After that we analyse the boot variable with the help of show bootvara and come to know that the config register value is OxAOO2. So we reload the hot standby module and after that we got the full config access and change the register value. After the booting of standby module , we ran the command “show redundancy” and got the hot standy module with full acces.