When creating new web part pages in SharePoint, the left nav / quick launch doesn’t always display.
To allow the quick launch to display do the following.
Open SharePoint Designer.
Open the page you want to edit.
Switch to Split view of the page and code.
— In SharePoint Designer 2010 you will see this option at the bottom left of the page.
In the code window, do a CTRL+F to find these three items, once found remove them.
2. asp:Content ContentPlaceHolderId=”PlaceHolderNavSpacer” runat=”server”>
Once you have removed these item, click save.