Configure the maximum file upload size
I have just tried to upload a fairly large file to a SharePoint Document Library but it failed because it exceeded the maximum supported size, as shown in the screenshot below. The exact error reads: "The specified file is larger than the maximum supported size"
I was able to easily increase the maximum upload size using the Central administration in a few easy to follow steps:
1. Login to the SharePoint Central Administration
2. Choose Manage Web Applications under the Application Management section
3. Select the SharePoint – 80 site and then click General Settings in the Ribbon
4. Scroll down the page and enter a new value, in MB, for the Maximum Upload Size. Click OK
5. Log out of the Central Administration