Virtual memory support in NT uses a system page file to swap pages from memory of different processes onto disk when they are not being actively used. On a running system, the page file is opened exclusively by the operating system and is well-protected. For the cautious souls out there, or with high-threat target PCs, one can ensure that any sensitive information from process memory is not left on the hard drive cache which could become available to a user booting the PC with another operating system, Clear Page File This could be particularly valuable on shared PCs.

A must have for NT administrators in corporate or governmental organizations or anyone being audited by a large outside audit firm.
It is not a secrets type guide but it has excellent sound advice and its used by PriceWaterhouse's auditors as a guide.