It's possible that the page file stored some confidential information...
so for safety reasons you may want to clear your virtual memory whenever you run a shutdown of the PC.
Run the application regedit.exe and select the following key:
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
edit or create (if doesn't exist) the following value:
"ClearPageFileAtShutdown"=dword:1
