One of my ipod's library/file have been deleted, how can I retrieve it?

a friend gave me an ipod nano, it downloads music and video. however, one of the library or maybe file was deleted automatically by my antivirus when I connected the ipod to my computer. now I can only download the audio, but not a video anymore, it seems that the file or library that was deleted has something to do with my video recording. the ipod comes with a driver disk, and no set up program for the ipod available in the disk. I found out later that the ipod was an imitation from the original one. all the program works fine except for downloading a video. I can download a video on my ipod before but now no more, may be because of the file that was deleted. the question now is how can I recover that lost/deleted file or library to my ipod? is there any chance of recovering the lost file so that I can again download video on the ipod? if so, how can I recover the lost/deleted file or library to the ipod? anybody have suggestions?

One of my ipod's library/file have been deleted, how can I retrieve it?ktm

nanos can't play video.

but should this happen with another ipod.

In Itunes:

1. Connect ipod to computer

2.when it pops up on the side in itunes click on it.

3. The latest version of Itunes should give you an overview of the ipod, look towards the bottom, should be something about restoring the ipod.

4. restore.

5. You should be all set.