Hi,
Thank you for posting this question in Microsoft Community.
To provide an appropriate resolution, I would need more information from your end.
1. Are you using Internet Explorer to download the files?
2. Do you have a wired net connection or a wireless net connection?
3. Did you make any changes to the computer prior to this issue?
Let us follow these methods.
Method 1.
Run a full computer scan with the Microsoft Safety Scanner to make sure that the computer is virus free.
Microsoft Safety Scanner: http://www.microsoft.com/security/scanner/en-us/default.aspx
Safety Scanner Disclaimer: There could be a loss of data while performing a scan using Microsoft safety scanner to eliminate virus if any.
Method 2.
Boot the computer in a clean boot state and check the download status. A clean boot helps to verify if any third party application service or startup item is causing this issue.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7, Windows 8:http://support.microsoft.com/kb/929135
Note: After you have finished troubleshooting, follow steps under “How to reset the computer to start as usual after troubleshooting with clean boot” in the article to boot to normal startup.
Let us know if you need further help with any Windows issue. We will be glad to help.