trying to flash MCX515A-CCAT to firmware Rev 16.24.1000 in windows pe 10.0.17134

[system]

Well - I rebooted my PC and then it worked! Stephen Rice - looks like you would use the setx command to set environment variable sin WinPE. Here is a link https://superuser.com/questions/621484/setting-environment-variables-and-appending-to-system-wide-path-with-a-windows