.menu {
    float: right;
    font-size: 18px;
    list-style: outside none none;
    margin-top: 10px;
}

.menu li a {
    color: blue;
    display: block;
    text-decoration: none;
}

.menu li {
    display: inline;
    float: left;
    padding-right: 23px;
}

<div class="divclass" id="div1"></div>
<div class="divclass" id="div1"></div>
<div class="divclass" id="div1"></div>

<div id="bigdiv">
   <div id="div1"></div>
   <div id="div2"></div>
   <div id="div3"></div>
</div>

<div class="main">
<div class="header">
    <img src="logo.png"/>

  <ul class="menu">
    <li><a href="#">Home &nbsp;&nbsp;&nbsp;</a> </li>
    <li><a href="#">Product Tour&nbsp;&nbsp;&nbsp;</a> </li>
    <li><a href="#">Pricing&nbsp;&nbsp;&nbsp;</a> </li>
    <li><a href="#">Try&nbsp;&nbsp;&nbsp;&nbsp;</a></li>
    <li><a href="#">Vision</a></li>
   </ul>
</div>

<div class="sub">
  <div class="product">
  </div>
  <div class="product2">
  </div>
 </div>
</div>