I'm not on my Win 7 laptop at the moment but I seem to remember that when the system shows the "Recovered from a problem" message, there was an option to see the details. Otherwise, have a look at the Event Viewer, (Control Panel > Administrative Tools > Event Viewer), and see what errors are shown at the times of the shutdowns.
I have heard, but have no personal knowledge, that Hibernation is better than Standby in many cases.
My new laptop is facing problems - unexpected shutdown in the Windows 7 64 bit. Every time when I leave my laptop before it goes to standby, it will automatically shut down and then restart. It will ask me to start in the normal mode or in the safe mode. After booting up, it shows me a pop-up window with a message "windows has recovered from an unexpected shutdown."
I do not know whether it is the software or hardware problem. Is it fixable? If it is the hardware problem, I can return the computer to the store. My computer has only ZoneAlarm Internet Security Suit and Webroot Spy Sweeper installed. Please provide a solution. Thank you.