Note this guide is for PC users only
To upgrade your Cowon O2's firmware just follow these steps.
1. Go to http://cowonglobal.com/
2. On the right side of the page their is a section called Whats New click it.
3. Then look at the list of firmwares. The higher up it is on the list the newer the firmware is. Look for one called Cowon O2 PMP Firmware V.(then it will say a bunch of numbers). Choose the one that is highest on the list or the one with the higher number. Example: V.1.16 is smaller then V.1.17 so choose V.1.17. Then click download. Then scroll about half way down the page and under Firmware/Software download it should say Cowon O2 PMP Firmware V(a bunch of numbers). Then right next to it in green "GO" Click this.
4. Something should pop up choose save and choose to save it on your desktop.
5. When it is finished downloading go to your desktop, right click on the folder you just downloaded and choose extract all. Something should pop up, choose next. And then choose next again. Make sure that the box is checked that says something like "show extracted files".Then click finish.
6. Something should pop up with a bunch of files in it. Select all the files by click Ctrl - A or by doing it any way you want then, click Ctrl - C in order to copy the files.
7. Then connect your Cowon O2 by using the USB cable.
8. Once it's connected, go to My Computer and then Cowon O2 and paste your files here by either right clicking then choosing paste or by clicking Ctrl - V.
9. Once its finished copying safely remove your Cowon O2 by clicking the little icon in your system tray and then choose safely remove hardware.
10. Then unplug your O2 and it should shutdown. Once its off turn it back on again.
11. Then something should be on your screen that says Firmware Upgrade. Just wait and eventually your Cowon will restart once it's done upgrading.
12. This step is not necessary from what I've seen, but its always safe to restart your Cowon one more time.
13. And now you've upgraded your firmware! You can delete the two folders on your desktop that you used for this since you have no more need for them.
Currently the newest firmware is V1.29 (last updated ), which you can download here.