Virtual memory support in Windows 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. To ensure that any sensitive information from process memory is not left on the hard drive and thus not available to a user booting the server with another operating system, apply the following Windows NT registry hack: Clear Page File. This could be particularly valuable on shared PCs. Note that this protection only works with a clean shutdown. The ClearPageFileAtShutdown is part of the normal shutdown process when this value is set.