Nero Vision not detecting vids.

I am trying to edit some video clips through Nero Vision. The files are in .mpg format. I am trying to make a dvd out of those files. But when i am trying to edit it through the `Slide Show` option it cant add the files and its giving out an error msg.

Plz help me in solving the problem.
Can anyone also recommend me a similar video editing software like Nero?
Thank U.