Hi Ffreniere,

If you shut down the computer, disconnect the BIAB drive, then turn the computer back on, is that ESP device still listed? If not, does it reappear when you reconnect the hard drive?

It looks like ESP is an EFI System Partition, so this may be a partition on your main hard drive, not the USB drive. The above test will tell us more.

https://social.technet.microsoft.com/Forums/windows/en-US/9612d18b-9be3-478b-a4ae-f0f934971b96/why-am-i-getting-a-new-drive-listed-called-esp-f?forum=w8itprogeneral

If it turns out that the ESP drive is something else, please try reseating the USB drive as shown in the following tutorial:

http://www.pgmusic.com/tutorial_hd-troubleshoot.htm

Your hard drive enclosure will likely be pretty different, and will come apart by removing the two screws on either side, near the end that the cable plugs into. The rest of the tutorial will still apply though.

Thanks
Kent
PG Music