To send photos/videos from your iPhone/iPad/iPod Touch to your PC just open PhotoSync on the device, select the photos/videos and press the red transfer button. Select "Computer" and choose your PC from the list of devices.
To send one or more photos/videos from your PC to your iPhone/iPad/iPod Touch right click on the PhotoSync Companion icon in the system tray to open the application menu and choose "Send photos/videos":
In the upcoming file dialog select the photos/videos you want to transfer and then press the "Open" button.
Hint: To select more than one photo/video at a time, some Windows knowledge is needed.
Now you will see a window that scans for available PhotoSync devices. If PhotoSync is running on your iPhone/iPad/iPod Touch in the same WiFi network it is shown in the list. Select your device and press "Send" to start the photo/video transfer:
A transfer window informs you about the ongoing transfer progress:
Send photos to iOS device using Send Menu
Send photos to iOS device using Context Menu