I have used Windows 7 x64 Ultimate on my desktop. All features worked properly.
Several days ago I obtained a notification I can upgrade my OS to Windows 10 so I did it.
As for now hibernation fails: when I power on PC after hibernation it shows Windows logo and power off again. After that I can start PC again and it boots in normal way (not the way it should after hibernation).
Some information about that.
1. Sleep mode works OK, no problem to enter and exit it - so no problem with BIOS settings.
2. "hiberfil.sys" file exists at C:, it correctly disappears and appears again when executing "powercfg –hibernate –off" / "powercfg –hibernate –on"
3. There is no "yellow" drivers in autostarts.
4. Video drivers for nVidia Geforce GTX 260 were updated to latest official "341.74-desktop-win10-64bit-international.exe" from official site.
Actually it looks like the system gets power off too early: I don't think 4 Gb of RAM can be stores so fast as it happens when I choose "Hibernation".