So I folowed this guide, so I can partition my USB stick. And the "flip removable bit" option made it look like a hard drive in my PC. It now always looks like a Hard Drive, and not for instance a: "removable storage"
The program I used to flip the removable bit is: Lexar's Bootit software. I tried to use the "flip removable bit" button a couple times again with my USB Stick. But it didn't revert it.
This is the guide. I had no idea that I couldn't undo it:
http://www.wikihow.com/Partition-a-Thumb-Drive
Any way to change it? Or time to buy a new USB stick?
To make for instance several bootable isos on one USB stick. Unfourtunately it was the wrong method, because if it is not being seen as a USB stick, the programs don't accept it. But it could be used otherwise, as I stated below.
Edit: Or you use it as a storage drive simply with partitions. Or install a program on it.