If you want to try out ChromeOS Flex without installing it on a physical machine and without a USB key, there are two crucial steps to follow. Firstly, properly mount the .bin live USB image in a way accessible to the VM. Secondly, set the graphics drivers to something supported by ChromeOS Flex to enable successful booting of the live USB image. Other important steps include downloading the ChromeOS Flex USB image, creating a VM with specific settings, and mapping in the live USB binary image as a disk. Following these steps will allow you to run ChromeOS Flex on a virtual machine hassle-free.
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