I was trying to reinstall Windows 10 on a lenovo desktop PC, by using Win10 Install Media usb key. I wanted to install to DISK 0. After deleting the existing main partition and then selecting the newly unallocated space on DISK 0, I'd hit next, and then see:
"windows setup - windows detected that the EFI system partition was formatted as NTFS. Format the EFI system partition as FAT32 and restart the installation"
I tried deleting the EFI partition on DISK 0, deleting the other partitions (system reserved, recovery)... They kept duplicating and reappearing (which indicates a different problem I'm sure)... Until finally I noticed that in addition to the DISK 0, there was my external USB drive, showing up as DISK 1, which had it's own EFI partition and a large data partition.
As soon as I unplugged the external USB drive, the EFI warning went away.
So apparently the presence of the other disk's EFI partition was confusing the installer?
Is this normal? Seems so dumb... Seems like if this is an issue (having a USB Drive plugged in while installing windows), there should be a warning saying, "make sure you remove external drives..." etc.
Edited by dgrrr, 09 January 2017 - 09:57 PM.