Item can get added to the New context menu sometimes when you install programs that add to it. It involves editing the registry so I would not do this if you are not comfortable in the registry.
If you wish to pursue it, then this tutorial will show you how to. You will need to know the file extensions of the items listed in the New menu you want removed. Post a screenshot of the New menu items, and I will see what I can do to help make it easier for you.
New Menu - Context and File
Hope this helps,