You can change this setting in web.config:
<system.web>
<httpRuntime maxRequestLength="102400" executionTimeout="360"/>
</system.web>
If this attribute set to limited size, can be used to prevent denial of service attacks (DOS).
Default value: 4096 (4 MB).
Maxium size: 1048576 (1 GB) for .NET Framework 1.0/1.1 and 2097151 (2 GB) for .NET Framework 2.0.
Reference:
http://msdn.microsoft.com/en-us/library/system.web.configuration.httpruntimesection.maxrequestlength.aspx
