1 The copy you got from the Save As option "Always create a backup".
2 The backup that your IT department made from the network drive.
3 The copy that you sent to someone by e-mail, or put on a memory stick
or a separate drive.
4 The earlier version that might be available in XP (through Properties)
if you are using a network drive.
If none of the above, you're out of luck and you'll presumably use option 1
above in future.