25.The images and the video is not clear

Please make sure the lens is clear,or you can use the fabric to clean the lens

26.After I connect on my PC, when I see the movie,I can hear my own voice,Can I make it disappear?

No,it can not,it record the audio and the images at the same time

27.How can I access into the video file?

Make sure your device is turn on,and then enter into the main screen,
then press the menu for choose the different menu, then you can see the video file in the device.