How to fix problems with ejecting USB after running Steam

Steam runs great from my USB (no lag, relatively short load time, sometimes even remembers my account so I don't have to put in the security code). However, after every time I play (CS:GO, btw), I try to eject the USB but it tells me that it is still in use. Even after closing all tabs and all programs it tells me this.

I thought I found a quick fix by pressing "Exit Steam" in the same location where you can eject USBs, but this only worked a couple times. After that, when I exited Steam I was still unable to eject. How can I consistently eject my USB to prevent any problems to my computer or my flash drive?

Steam is most likely still running in the background. If any games are downloading stop or pause them. Then, try to exit steam. If you still cannot eject your flash drive, open task manager and abort any steam processes happening in the background. That should fix any issues you have with ejecting your drive.