is possible upgrate windows 8 to windows 8.1 with HP Client Automation, if yes wich is the procces to follow.
yes, it is possible. If you have HPCA agent installed on the target computer. Assign Windows 8.1 in the policy and trigger an OS deployment job from the core console on this target machine. There is a notify option to do so. You can try this first on one machine and duplicate the steps on others.