if you need to upload larger files, you will need to alter this value by changing the httpRuntime maxRequestLength property to the desired value; at the same time you may need to increase the executionTimeout property to a greater value as well in order to support longer upload times. Take care when altering the values as Microsoft has established the default 4 MB limit to provide some safety against attempts to upload extremely large files that may hamper access to the server.
i got this by C:\WINDOWS\Microsoft.NET\Framework\v2.0.50727\CONFIG but i dint find the parameters whose value i need to change.. "executiontimeout" and "maxRequestLength"...can anyone pelase help me with regard to this ?