Recover a previous version of a document.

Windows Vista introduces a new feature: Previous Versions. This allows you to “roll back” the clock to an earlier version of a file that you may have accidentally
saved over or edited. In the Documents Explorer, open a document, edit it, save it, and then close it. While selecting the document, choose the Previous Versions option on the command bar, which will bring up a list of previously
saved versions of the individual file. Choose a previous version and Windows Vista will restore your file to that version. Careful: all edits since that version will be lost.