Some versions of windows and some web browsers - particularly Internet Explorer - do not support HTTP downloads larger than 1gb.
Here is a google search for some results that may help you:
https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=cannot%20download%20files%20larger%20than%201gb
You may need to have some IT help to get everything updated.
Also check your internet connection and your browser settings. For example, Safari on Mac has security/privacy features that can allow or deny downloads from unknown websites. Under "Websites" in "General" make sure that "Downloads" are not set to "Deny" otherwise you will not be able to start a download Reset your website settings to "Allow" to successfully download the files.
