Hi, and thanks for taking the time to consider helping me out! Here are the symptoms: • my early 2013, 13" Retina Macbook Pro running Sierra will only boot in safe mode • when booted, the comp feels slow (e.g. I can't boot a program from finder because it doesn't find it) and graphics seems chopped. I don't know if this is due to safe mode, or if it part of the core problem • BEFORE this happened, my shift-keys (not caps lock key) acted weirdly, sometimes getting stuck in caps, then not functioning at all. They are not held down physically, just to be clear. Here's where I get stuck: • my guess is/was that there's something wrong with the shift-key and that the comp only boots in safe mode because of it (holding down shift during startup is the command for a safe boot) • I want to try a fresh install, but I can't get the MBP to boot from my flash drive with the Sierra installer on it! So, do you have any idea what may be the core problem and/or how to proceed? Is the shift-key stuck and therefore overrides the command to boot from an external drive? Thanks!