I have just updated my PMB software to the latest Play Memories Home. I find the calender operation not as good and as quick so therefore my question is is it possible to revert back to the original PMB software
If you use the Add/Remove programs feature of Windows to uninstall Play Memories and then run the original PMB disc that came with your camera, this should allow you to use the previous version of PMB.
If you do not have the disc, let me know the model of your camera and I will hopefully be able to provide you with a PMB download link.
If you follow the uninstall procedure for the PMB software you shouldn't lose your photos as they will be in a defined folder. However, as with anything involving computers, I would advise you to back everything up first just in case.