I was looking for this matter and thanks to the author of this blog(kimwoodbridge) which helped me to get it done.Well while adding adsense search for my blog i have to create a page which is necessary to show the search results,it was done successfully but it also added that page name on my top navigation bar which when clicked was showing 404 page because no queries were sent through google search box.Then i realized that the link should not be placed on the nav bar. So i decided to remove it,for it i google’s and got the answer.I am not a big coder so i just keep the stuff’s simple.

Open Header.php or if the navbar is shown on side then sidebar.php

Here is the tutorial

Pages are displayed with the following code, which is generally used in the header, footer, or sidebar.

This will list all of your pages until you add conditions in between ‘()’. You need to use the exclude condition and find out what number ID each page has. The exclude code looks like
You can see that you have added ‘exclude=17,38′ to the original
list pages code.

Of course, we need to locate the correct ID numbers for your pages.

Go to Manage > Pages and select the name of the page in which you would like to exclude. In the address bar of your web browser will be a URL that looks like the following.

http://www.yoursite.com/wp-admin/page.php?action=edit&post=96

The number at the end, 96, is the ID number for the page and is the number you will use in the exclude code. You can do this for each page that you want to exclude as long as you put a comma between the page numbers in the code.

Source : www.kimwoodbridge.com

well though it was clear but my template was a bit different and with different code it was calling this function $exclude in another way so i tried this code

370 is page id

thats it.