4
Just goto your module admin
Admin ---> system admin ---> Modules.
You will then see a colum titled 'Order (0 = hide)'
By making them 0 this will hide the menu item and all sub menus for that module in the main menu block.
So choose the module then add 0 to order and click submit to make changes and verify, thats it module link removed.
Hope this is of help.
[EDIT]
Looks like JackJ beat me to the answer, lol never mind