At times, our machines restart due to a patch or when the browser crashes and we are not able to bookmark or remember the windows that were open. This can be very painful when we have opened several browsing tabs and do not get a chance to save them. Fortunately, Chrome stores the window details along with all the tabs that were open in the window instance.
In case you ever need them, just go to Menu -> History and you will see the last-opened windows (with the number of tabs mentioned) under the Recently closed section.
