Unable to install any Application

The issue could be with ePO for McAfee VirusScan

1.Click Start > Run.
2.Type cmd and press Enter.
3.Type cd\ and press Enter.
4.Type cd program files and press Enter.
5.Type cd mcafee and press Enter.
6.Type cd common framework and press Enter.
7.Type frminst /remove=agent and press Enter.
8.The McAfee Agent and Updater Setup window will open and begin removing ePolicy Orchestrator

http://www.helpdesk.ilstu.edu/kb/index.phtml?kbid=1217

1.Make a backup of your registry before you begin. Proceed with these instructions only if you are confident about what you are doing.

2.Click Start > Run.
3.Type regedit and press Enter. This will open Registry Editor.
4.Double-click HKEY_LOCAL_MACHINE > SOFTWARE.
5.Locate the McAfee registry key and the Network Associates registry key. You may have one or both of these.
6.Expand the McAfee and Network Associates registry keys to inspect their contents and sub-keys.
 
 If you have McAfee or Network Associates software installed on your computer apart from McAfee VirusScan and McAfee ePO, then you should use caution when considering whether or not you want to delete these registry keys. If you delete these registry keys, you may find that other McAfee or Network Associates software no longer functions as expected. If you are sure that you do not have any additional McAfee or Network Associates software installed, delete the McAfee registry key and the Network Associates registry key.