http://www.sysinternals.com/ntw2k/source/filemon.shtml
 
"Filemon monitors and displays file system activity on a system in real-time. Its advanced capabilities make it a powerful tool for exploring the way Windows works, seeing how applications use the files and DLLs, or tracking down problems in system or application file configurations. Filemon's timestamping feature will show you precisely when every open, read, write or delete, happens, and its status column tells you the outcome. Filemon is so easy to use that you'll be an expert within minutes. It begins monitoring when you start it, and its output window can be saved to a file for off-line viewing. It has full search capability, and if you find that you're getting information overload, simply set up one or more filters."