To hide the left navigation menu on your customized or default Master Page one things will have to be done:
- Create or Modify a Page Layout.
On the Page Layout, simply overwrite the Content Place holder "Asp:PlaceHolderLeftNavBar".
Then with some additional styling you will have a full page layout with no left nav-bar. Simple and efficient and pure ASP.NET.
Example
Place this in your PageLayout.aspx file.
<asp:Conent ContentPlaceHolderId="PlaceHolderLeftNavBar" runat="server"/>