Canonical has temporarily pulled the download links for Ubuntu 17.10 "Artful Aardvark" from the Ubuntu website due to ongoing reports of some laptops finding their BIOS corrupted after installing this latest Ubuntu release. The issue is appearing most frequently with Lenovo laptops but there are also reports of issues with other laptop vendors as well.
This issue appears to stem from the Intel SPI driver in the 17.10's Linux 4.13 kernel corrupting the BIOS for a select number of laptop motherboards. Canonical is aware of this issue and is planning to disable the Intel SPI drivers in their kernel builds. Canonical's hardware enablement team has already verified this works around the problem, but doesn't provide any benefit if your BIOS is already corrupted.
A respun Ubuntu 17.10 release with the updated kernel is expected, but as of writing the download page is still discouraging the use of 17.10