Tracking changes is built into MS Word: http://www.fgcu.edu/support/office2007/word/changes.asp
But I suppose it isn't activated in that document.
But if you know the change date/time (shown by Explorer), you might be able to see in the Event log who was or were logged on at that moment.
That's all Windows has to offer. Remember the P in PC stands for Personal.
Microsoft made MS Sharepoint as a DMS (Document Management System) and there you can see such things.
We have one sharing folder in windows xp system, one of my colleague edited one word file. is there any tracking method to find out which user,date & terminal made the updations.
Sharing folder is having full access to seven people. Local policies are not defined in this PC.