This client has three backup selection i.e C drive,D drive & Shadow copy components.backup is succesful for C & D drive but for shadow copy components failing with 54 error code.
Check to see that the client's OS is correctly listed in the backup policy, check if Volume Shadowcopy Service has been disabled on the client (try setting it to manual if it is) if it's Win 2003.
Finally issue got solved.The server was not rebooted for the past 3 months.After rebooting the server, shadow copy components were backuped successfully.