So you cannot upgrade to Windows 10, so what. Windows 8.x has worked fine for you up till now will continue to work until the device dies. Everyone goes ballistic because they can’t upgrade. The Intel Atom Z2760 was a locked down platform from the beginning and when buying it you should have realized that. Very simple, don’t buy anything with an Atom CPU in it.
Window 8.1 will continue to get updates as the years go by so you are not in danger of the device not getting support. It is simply you want something from it and for it, and from the manufacturer that they simply do not want to be bothered with. When you bought the Atom Z2760 device you should have had the forgone conclusion it was obsolete from day one, as all computer hardware usually is. Read Atom Z2760 review.
I have a netbook with an Atom CPU and it has the X64 bit extensions in the CPU to run the Windows x64 versions. But Intel refuses to make an x64 driver for the GPU. Why, Maybe because in x64 mode the Atom runs allot better than in x86 mode. It would allow you to use more RAM, again something they don’t want you doing on an Atom CPU. Because of the 32bit version of Windows it is limited to 3.2GB of RAM of course. I have a 4GB stick in it and that extra memory goes unused because I can’t fully run the 64 bit version on it. At least with any video acceleration that is.
I am not saying that running x64 bit Windows on an Atom is going to make it run like an i3, but you have to wonder why they are hobbling the Atom like they are. Why did they even put the x64 bit code in the dam thing if they, Intel, were going to never release the x64 bit video driver for it. I guess it would be for those rare servers that are using dozens of Atom CPUs in parallel that do not even use the GPU. That is the only thing I can think of.
So in the end stop complaining about not being able to upgrade to Windows 10 on your device. There may be very good reasons as to not upgrade. Maybe Windows 10 simply may end of life your device early if you use it. I stated in post the other day that I lost and older notebook to Windows 10 insisting on using the wrong sound chip driver and burning the chip out. There are reasons not to upgrade a device that was never really meant to run that OS. So in the end think more as to the reasons that an OEM may not want to support Windows 10 on your device before going crazy about not being to have the shinny new version of Windows.