System restore doesn't make an unlimited number of restore points. There is a good chance you don't have one that goes back to the month of December. Look at the calendar and see if any of the dates are bolded. If so, click and see if there is a valid restore point. But don't be surprised if they have been purged to make room for new ones.
I have been trying to "restore" to a point in Dec 2004 but my options are only Jan 2005. How can I get back to 2004? Thanks, VA Gail

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