This can be accomplished veru easily by making use of System.Environment class. This class has a property named Version. This returns the version of framework installed on the system. The information is stored in the following format.
major.minor[.build[.revision]]
The current version of framework is 1.0.3705.0. Therefore if you call this information and call ToString method on Version object, you will get the string representation of version information.

private void Page_Load(object sender, System.EventArgs e)
{
	// Put user code to initialize the page here
	if (!IsPostBack)
	{
		Version vs = Environment.Version;
		Response.Write(vs.ToString());
	}
}											
											

The answer to this question is yes and no. At runtime, .Net framework checks the maximum size for the request object. This information is obtained from the application's condiguration file. If this limit is not specified in web.config file, then it is obtained from machine.config file. By default this limit os set to 4096KB.

<httpRuntime executionTimeout="90"
	maxRequestLength="4096"
	useFullyQualifiedRedirectUrl="false"
	minFreeThreads="8"
	minLocalRequestFreeThreads="4"
	appRequestQueueLimit="100"/>
										

To modify this limit, you can change the number in machine.config. but preferably, create the entry in your application's web.config file.

When you want to control the columns that DataGrid should render, set the AutoGenerateColumns attribute to false. If you are using design time support or directly specifying this value in asp:DataGrid tag, then it works fine. But if you want to set this attribute value, make sure that you do it before the control is data bound. Otherwise it will have no effect and all the data columns will get rendered.

myGrid.AutoGenerateColumns = false;
myGrid.DataSource = CreateMyDataSource();
myGrid.DataBind();