Comment 7 for bug 1734147

I can also confirm this. I use the Lenovo Z50-70 laptop and I have encountered this problem. After installing Ubuntu 17.10 (and other remixes of it) and reinstalling it again, the UEFI BIOS does not save any changes except the date and time. I could not reset the UEFI BIOS settings because it did not save any changes and the CMOS battery is soldered, unfortunately. What is even worse, the UEFI BIOS does not boot any bootable media. I tried booting DVDs, USB sticks and other HDDs with no luck. The only thing that the boot menu shows is the old installation partition name and nothing else. Before that happened I used Manjaro distribution which did not have such problems even after reinstalling it multiple times. By the way, the solution to this problem was the a motherboard replacement... Two times.

The only way to boot bootable devices is to install and properly configure rEFInd: https://forums.lenovo.com/t5/forums/v3_1/forumtopicpage/board-id/ll04_en/thread-id/154203/page/2. That does not solve the UEFI BIOS corruption problem. It is just a workaround.

Maybe it is a defective Lenovo UEFI BIOS (two motherboard replacements proved that it could be defective "by design"). However, as I mentioned before, other distributions had not caused any of these problems before.