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 PC with another operating system, apply the following Windows NT / Windows 2000 / Windows XP registry hack:

Hive: HKEY_LOCAL_MACHINE
Key: SYSTEM\CurrentControlSet\Control\SessionManager\Memory Management
Name: ClearPageFileAtShutdown
Type: REG_DWORD
Value: 1

Note that this protection only works with a clean shutdown. The ClearPageFileAtShutdown is part of the normal shutdown process when this value is set. Valuable for shared PCs or if you have something very valuable needing protection.