How to make a specific field wider within the gridview?

Question

    <asp:BoundField DataField="ComputerModel" HeaderText="ComputerModel" 
    SortExpression="ComputerModel" 
    ItemStyle-Width="50px"/>

    <asp:CheckBoxField DataField="Lease" HeaderText="Lease" 
        SortExpression="Lease" />
    <asp:BoundField DataField="SerialNumber" HeaderText="SerialNumber" 
        SortExpression="SerialNumber" />
    <asp:BoundField DataField="LeasedTagNum" HeaderText="LeasedTagNum" 
        SortExpression="LeasedTagNum" />
    <asp:BoundField DataField="MonitorType" HeaderText="MonitorType" 
        SortExpression="MonitorType" />
    <asp:BoundField DataField="MonitorCount" HeaderText="MonitorCount" 
        SortExpression="MonitorCount" />
    <asp:CommandField ShowEditButton="True" ShowInsertButton="True" />
</Fields>
<HeaderStyle BackColor="#507CD1" Font-Bold="True" ForeColor="White" />
<EditRowStyle BackColor="#2461BF" />
<AlternatingRowStyle BackColor="White" />

Answer 1

Try something like this:

<asp:BoundField DataField="ComputerModel" ItemStyle-Width="50px"/>

where 50px is the width you need.

Answer 2

Try this:

<asp:BoundField DataField="ComputerModel" HeaderText="ComputerModel" 
        SortExpression="ComputerModel" 
        HeaderStyle-Width="50px" >
</asp:BoundField>

Answer 3

Can we see all the HTML for the control? I'm curious to see the markup for the entire control so I don't make any assumptions.

Per MSDN try

 <asp:boundfield
        sortexpression="LastName"
        datafield="LastName"
        headertext="LastName">
          <itemstyle width="50px">
          </itemstyle>
      </asp:boundfield>

I would like to see what you have thus far and maybe I can be more helpful. Also is there any CSS class that may be setting the item width?