I'm trying to upload large file on IIS7 (Windows Vista/Windows 2008) but I'm getting HTTP Error 404.13
You need to change a special option in IIS called maxAllowedContentLength to allow uploading larger files
To resolve this problem, follow these steps:
1. Click Start. In the Start Search box, type Notepad. Right-click Notepad, and then click Run as administrator.
Note If you are prompted for an administrator password or for a confirmation, type the password, or click Continue.
2. On the File menu, click Open. In the File name box, type %windir%\system32\inetsrv\config\applicationhost.config, and then click Open.
3. In the ApplicationHost.config file, locate the <requestLimits> node.
4. Remove the maxAllowedContentLength property. Or, add a value that matches the size of the Content-Length header that the client sends as part of the request. By default, the value of the maxAllowedContentLength property is 30000000.
For example, modify the following configuration data inside the <requestFiltering> section.
<requestLimits maxAllowedContentLength ="<length>" />
5. Save the ApplicationHost.config file.
For more information see: http://support.microsoft.com/kb/942074/
More info about content filtering in IIS:
See also for more info
For Windows 2003 see this FAQ