I don't know how this partition was created. Only I am using this computer, so I thought it is probably from some software program that I've installed. I've uninstalled all programs but this partition is still there, I still can't remove/format/delete it.
It is 300MB and as you can see in the picture it has some used space. But when I open it, it is empty.
Tried with Disk Managment on Windows 7 and no luck.