How do I remove the ISO from a USB drive?

So after succesfully using Balena Etcher to flash an image to a USB drive and installing Lubuntu on a laptop, now I can’t seem un-flash the drive. I’ve re-formatted it, made a new partition table, and there doesn’t seem to be anything there. Except that it is a 16GB drive and now it shows up as 14.4GB. But if I leave plugged in, the computer will still boot to the Lubuntu installation. Any suggestions?

Hello, just to be sure can you try the steps outlined in the “How to Recover a USB Drive or SD Card” section from this post: Etcher killed my USB stick … or did it? and let us know if it still appears to be flashed with the previous image and/or not completely empty?

Hi, did you manage to recover your USB as advised by my colleague? Let us know if you need more assistance with this.

Hello. Yes, It is working fine now. Although I think I actually fixed it before trying his suggestion by doing something else: I “flashed” an empty text file to it. But later I tried the other method, with Linux, to be sure, and it seems to be fine now. Thanks!