You are worrying over nothing..
While the system up and running the pagefile.sys will be locked by windows and by no means you will be able to unlock it.. So you don't need to worry as the contents of the pagefile cannot be read by a hacker while the system is up and running... The only way through get access to the page file is to boot from floppy or connect the drive as a secondary hdd in a computer...
there are some tolls available to read the contents of the pagefile if you get access to the file.. They are called as forensic tools..
And yes you can ask the windows to clear the page file for you while it is shutting down.. Have a look at this link..