Format for comments in your code is wrong, correct format is:
<!--Comment-->
All the tags with ! in them appear to be comments and need to be fixed.
>here is the code where i have and error in "!Menu" adn other parts and i pste it from a book of microsoft
>
>
><Window x:Class="Browser"
> xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
> xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
> Title="My Own Wpf Browser" Height="480" Width="640" Name="Browser"
> Icon="face02.ico" SizeToContent="WidthAndHeight"
> WindowStartupLocation="CenterScreen" >
>
> <Grid Name="grid1">
> <DockPanel x:Uid="DockPanel_1">
> < !Menu Bar>
> <Menu x:Uid="Menu_1" Background="White" Name="_MainMenu" DockPanel.Dock="Top">
> <! Navigate Menu>
> <MenuItem x:Uid="NavigateMenu" Header="_Navigate" />
> <! Help Menu>
> <MenuItem x:Uid="HelpMenu" Header="_Help">
> <MenuItem x:Uid="AboutMenu" Header="_About" />
> </MenuItem>
> </Menu>
> </DockPanel>
> </Grid>
>
></Window>
>