Hi,
This file is a Nero video file. When you shot the video, was it with a camcorder? If so, your camcorder manual should explain what you need to edit the file, and possibly how to change it to another format.
If you have a Nero software version on your computer, you might want to check out this link:
http://www.click-now.net/downloads08.htm
It offers, under the link "NeroMix", a download for editing files, with codecs built in for WMV files as well.
Again, if you have the manual for your video equipment, it should tell what format it uses, and what software you need.
Best of luck.