We would suggest you please refer the technote link 274253 and also the URL :- http://www.veritas.com/softwaredownload and try downloading Backup Exec v10.0 on another test server and verify the result.
----------------------------------------------------------------
As an additional reference:-
Internet Explorer users have an ability to enjoy the additional feature, Download Manager. Download Manager provides the users with features such as start-stop, tracking download status and downloading of multiple files.
If you do not wish to use Download Manager, please select "No" when the dialog box appears and deny installation of Download Manager on your system.
In order for the Internet Explorer users to take advantage of Download Manager feature, there are few important browser security setup considerations:
Tools->Internet Options->security tab, under "Custom Level"
1. ActiveX controls and Plug-ins Section:
Download Signed ActiveX controls must be "Enable" or "Prompt"
Run ActiveX controls and Plugins: Enable or Prompt Script ActiveX controls marked safe for scripting: Enable or Prompt 2. Downloads File Download: Enable 3. Scripting:
Enable Active Scripting: Enable
Tools->Internet Options-> Privacy
Privacy setting cannot be "High" or "Block all Cookies"
If the Internet Explorer is not setup properly, it will result in the browser displaying either error message or blank page. In some situation, your network will not allow you to modify any Security and Privacy setting. Please contact your System Administrator for additional information.
In order to remove the installed Download Manager, delete the file named: Download Manager Control.
----------------------------------------------------------------
Once you sign on to Veritas website at http://www.veritas.com/softwaredownload , please make sure you come across a page where you have a "download tab" on the right hand side top corner of the web-page. Once you click on download now, another page would consists of terms and conditions where in you will have to click the box "I agree". Once you click on I agree, you will be forward to another page which mentions "Software Download". Its here you can choose Veritas Backup Exec v10.0 and download the same.
We hope this helps. Let us know if the problem still exists and revert back with the error message.