IE will no longer launch another app, it gets a permissions error?

When I try to download a file with IE 7 from a web site I get the “Open or Save Box”. I try to open (the appropriate program.. this has happened with Quicken and Winrar) and I get the following message.

“Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.”

This just started and I have no Idea what has happened. Any suggestions ?