This is not a Unigui Problem. It's a IIS 7 and above.
To solve this:
Open IIS 7 Console Select the website you want enable to accept large file uploads. In the main window double click 'Request filtering' once the window is opened you may see on top a list of tabs eg: file name extensions, rules, hidden segments and so on... regardless the tab you select, in the main window rightclick and select "Edit Feature Settings" and modify the "Maximum allowed content length (bytes)"
Restart IIS.
Now you can upload files larger than 30 MB ....
Thank's
Alfonso