I have Windows XP Pro, I recently experienced a "physical memory dump" (don't know what that means). I did some research and still didn't find a definition, but it was suggested that I should restore my computer back to an earlier date, before the memory dump. Well, I tried, but system restore does not work, when the computer restarts, there is a notice that says no changes have been made to your computer, use a different restore point. Different restore points don't work either. What do I do?