Hibernation is a way of shutting down and restarting your computer much more quickly than doing it the normal (proper) way - it is a time saver. It works by using a reserved area of disk equal to the size of RAM and the contents of that RAM, including system state, is saved on disk before powering down. Restarting the computer (coming out of hibernation) causes the RAM image to be read from disk into RAM - much quicker than starting the system in the normal way because previous system state is instantly available. Hibernation is more usually associated with laptops and conserving battery capacity.
The BIG drawback with hibernation is security. All system state and data in use is stored in clear - no encryption - so someone could examine the RAM image on disk for all sorts of secret and confidential stuff. The page file is also a vulnerability as use of hibernation depends on the contents of virtual memory being in the same state as when the system went into hibernation so you can't wipe the page file and succssfully rewake from hibernation.
The other drawback is that constant use of hibernation means that problems like application memory leakage are not corrected by the cleansing effect of a cold start. A software glitch might need a restart to eliminate it. Automatic spyware and virus scans (of memory and registry) often take place at startup. This would not happen with constant use of hibernation.
I would not use hibernation for the above reasons. Patience is a virtue, especially when starting Windows. I do however make much use of 'Standby' to save power because it IS secure, a password needing to be supplied to get access to the working state of the computer.
Null illegitimus carborundum
