I accidentally deleted everything on my hard drive when I was trying to install ChromeOS Flex. Now, I can't even boot from my USB to install Windows, and it seems like the Windows Boot Manager isn't working either. I really need some assistance here!
2 Answers
I get that you have a Windows USB ready, but if it won't access your operating system, that’s probably due to issues with the boot manager. You should boot from the Windows installer USB and try to install from there. If needed, wipe the drive during the installation process. I had to go through this too after installing ChromeOS, and it was a hassle, but you can definitely get Windows back up and running!
It sounds like ChromeOS Flex really took over your system. You might need to create a Windows USB using a different computer to get things back to normal. Make sure it’s set up correctly before trying again.

That sounds frustrating! Did you try using rEFInd as your boot manager? That helped me set things straight after a similar mess.