Maximum file size and time-out period for uploaded files
The default maximum file size for uploaded files is 4MB. The following code appears in the Web.config files for all activities that provide facilities for uploading files (these files are in C:\InetPub\wwwroot\SPSSMR\ActivityName). It sets the maximum size of files for uploading to approximately 256MB and the time-out period for uploads to 600 seconds (10 minutes).
<location path="filename.aspx">
<system.web>
<httpRuntime maxRequestLength="262144" executionTimeout="600"/>
</system.web>
</location>
To specify a larger or smaller file size, change the value of maxRequestLength. The maximum acceptable value is 2GB, or 2097152KB. However, be aware that the usual reason for restricting file size is to avoid Denial of Service (DOS) attacks.
See also