Usb to Usb connection of PCs is not possible. If you have Ethernet ports – connect PCs via them, but in case of Usb – only option is to use usb – ethernet adapters, this way it will work.
@breno
You can understand why PC to PC by USB is not possible. Just think about the following fact: when you are plugging device into USB (for example, Android device) you can see plugged device internal storage, but not PC’s storage. That’s because USB was designed with a Master/Slave relationship. Master (computer) known as Host, talks to simpler peripherals, which are Slave Devices.