In windows server 2008 it is possible to see how man open files there currently are on the system. This is useful if you need to reboot the system and don’t want to inhibit a users work. Rebooting a server while files are still open can cause data loss, so this is something that should be avoided. To see a list of open files
Start -> Administrative Tools -> Share Storage Management
You also have the option to close the files cleanly before performing a reboot.