I have an HP ProBook 4530s laptop running Windows 7 Professional with t secure boot firmware, so from the thread so far, as I purchased round about the date this thread it is unlikely that a firmware download will solve this. So I presume I just ignore the warning and do without the secure boot?
HP have been no use whatsoever.
I have the same problem plus screen size/resolution with a sonyVIAO that cost me 1500-00 + when new so that one may well go to Linux when support for win 7 falls away.