...not possible without close integration with the operating system and may still leave some data unprotected. To accessencrypted files, the user has to have the appropriate key available. This means that the user cannot focus only on the primary...
http://www.computerweekly.com/Articles/1999/08/19/178918/access-is-denied.htm
...content is automatically encrypted in background, transparently to end-users. Unique to Check Point, users can accessencrypted media securely on unmanaged computers with no client installation. This plugs potential leakage points and logs...
http://www.securitypark.co.uk/security_article263728.html