A zero-day security patch for Internet Explorer versions 9 to 11 is reportedly bricking Lenovo laptops. This patch, known as KB4467691, is apparently preventing mobile PCs of this brand with less than 8GB of RAM from starting Windows. There is no official fix for this issue at the time of writing.
https://www.notebookcheck.net/Internet-Explorer-security-patch-is-reported-as-dangerous-to-many-Lenovo-laptops.387561.0.html