I used my USB drive to install SecurityOnion and now it’s all messed up.

I tried formatting it in Windows and adding the files I wanted to transfer, but the linux boot stuff still showed up.

Formatting didn’t help, fdisk didn’t help. disklabl showed only the c partition as an ISO9660 partition, which could be mounted, but showed me the wrong stuff.

Using disklabel to change the c partition to unused did not help. Does dd help? YES!

# dd if=/dev/zero of=/dev/sd4c

That seemed to help. I can now read my files! Yay me!