you just need to get a video converter to help you, I always use Movavi Video Converter,
* Unique editing features: Split, Merge, Crop, Rotate, Adjust, Add Watermark, Photo Gallery.
There is free download link,
http://www.flash-video-soft.com/movavi-v…
hope it helps u,

there are many softwares to do it
first try WINDOWS MOVIE MAKER , u can do everything in that
or
u can try TOTAL VIDEO CONVERTER u can do Wat u asked and u can even convert it into another format .
or
use VCD cutter
or
BLAZE MEDIA PRO
or
U have a option in nero itself , u get it when u install the codec ……..

enjoy …………………………….

JIAO VCD Cutter is there
moreover u can use windows movie maker to cropp avi format video files