That's a pretty big file. You're likely to be having either a timeout problem (due to the speed of your internet connection), or you haven't configured asp.net to allow files as large as that to be uploaded. Take a look in your web.config file for the maxRequestLength attribute, it controls maximum file upload size i.e.

maxRequestLength="61440"

will allow 60MB uploads.

I would recommend that you don't use normal upload type modules, as they will stream the files to Ram, which can be a problem. Modules such as this utilise httpmodules that stream files to disk.

Cathal