UPDATE (5.4.18): The GeForce 397.55 Hotfix driver is now available and should rectify the issue.
NVIDIA released the GeForce Game Ready 397.31 driver package on Wednesday, bringing optimisations for BattleTech and FrostPunk as well as Vulkan 1.1 API compatibility and initial developer support for NVIDIA RTX Raytracing. Unfortunately reports from the official NVIDIA support forums indicate that something major fell through the cracks, causing reboot loops for some users attempting to install the driver package.
The symptoms are simple, but no less aggravating. Once the install process is complete users are prompted to restart their system, but the driver is improperly installed upon restart. This process then loops as the driver is 'found' and a restart is again prompted for.
At present it appears that affected systems are those powered by NVIDIA GTX 1060 GPUs, potentially isolated to AIBs Palit, Gainward, Zotac and PNY. It doesn't appear that other SKUs are affected by this bug specifically.
As a workaround, users are advised to boot into Windows Safe Mode and uninstall the driver using a utility such as DDU, which should clean out all trace of it. Then, after rebooting, you should be able to install the previous driver (v391.35 - WHQL.
Furthermore, support for NVIDIA's Fermi architecture was retired with this driver package, but some users either didn't get the message or misidentified the architecture their GPU was built on. Chief culprits are rebranded and OEM models low in the 600- and 700-series naming scheme (such as the GT610), and is a rare instance of NVIDIA's rebranding from previous architectures coming back to bite their customers. Attempting to install the driver generates an error which doesn't do a good job of explaining the issue.
SOURCE: NVIDIA Support Forums.