I seems like what you have found is your pagefile or hibernation file. IIRC these files actually have a path (c:/pagefile and... don't know), but they are special system files. You need to uncheck some checkboxes in the appropriate menu to make them visible.
In Windows XP all you need to do is:
- Open a Windows Explorer window. Open
the Extras menu and select
something like options at the bottom
of the menu.
- The second tab
(Display or View) contains a lot
of checkboxes.
- Try deselecting Hide
protected system files.
It should be almost the same workflow in Win7. I'm sorry i can't supply you with the right menu names. I use a German system.
You should now be able to see the files c:\pagefile.sys and maybe even c:\hiberfil.sys.
You can get rid of hiberfil.sys by disabling the hibernation mode (>System Preferences/Energy Options/Hibernation Tab/ > UNcheck checkbox). Pagefile.sys is required by the system.