Windows uses this file as virtual memory / extra ram. Lets say that you are working on a highly confidential MS Word doc. When you load this document it is loaded into ram. To save ram windows places certain items in the pagefile. With some effort, the pagefile can then be opened and the document can be extracted as well as any other open program or files. However Microsoft has implemented a feature that will clear the page file but they do not have it enabled by default. Please note, this will significantly increase the amount of time it takes to shut down your computer. We don't necessarily recommend this tweak, but we offer you the option if you want it:
Start Regedit. If you are unfamiliar with regedit please refer to our FAQ on how to get started.
Navigate to HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management
Select ClearPageFileAtShutdown from the list on the right.
Right on it and select Modify.
Change the value to 1 to enable.
Reboot your computer.