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What is the difference between Shutdown and Sleep in Windows 8? I am opening lots of documents, code editors, browser with many tabs so what I have seen is, when I Sleep the computer and switch ON next day, all the states are saved.

I don't want to lose the state of the previous day work. Is it safe to sleep the computer and power off?

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2 Answers 2

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Based on your comments to Julian's answer, I get the impression you're using a desktop computer. By default, desktop machines use a type of sleep called "Hybrid Sleep". You can verify this by using the Power Options control panel:

  1. Click Change plan settings next to your current plan:

    enter image description here

  2. Click Change advanced power settings:

    enter image description here

  3. Check that Allow hybrid sleep is on:

    enter image description here

This differs from normal sleep mode by effectively hibernating and sleeping at the same time. This means that your session remains in memory, but is also saved to disk.

Under normal circumstances when power is continuous throughout the sleep, the system resumes straight from memory as it is the fastest way to do so. In the event of a power outage or you remove power to the system this memory is cleared, and so the system resumes by loading back into memory from disk.

Other than advice I would always give which is to make sure you save your data before sleep (as resuming much like anything can sometimes fail) it is perfectly safe to use in this scenario.

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accepted, thanks Graham. –  Madan Sapkota Jan 22 '13 at 2:09

Sleep mode simply pauses the computer. Power is kept supplied to the memory (RAM) in the computer so that everything is still in place but nothing is changing.

Powering off, forces all of the applications to close before shutting down the computer completely. Everything in progress is ended. All reasonable applications on the computer will try to save all in-progress work first. Often you will be asked if you want to save things. If you don't the work is lost.

Sleep is generally much faster and is reasonably safe - AS LONG AS - you dont leave a laptop in sleep and not attached to the mains for more than a couple of days. Sleep mode still uses power, if the power is lost, so is your data. Powering off is always safer but much slower.

To avoid issues when sleeping a laptop, simply make sure everything is saved before you sleep the computer.

UPDATE: There is a third option, "Hibernate". You might need to turn this on in the power settings for the laptop. In this mode, the computer saves the current state of the active memory onto the hard disk and then powers off. When you restart, it reloads the memory from disk. This has the advantage that it requires no power from the battery or mains. However, it is somewhat slower to into and out of.

So quickest is Sleep but it needs a bit of power to keep going. Great for getting out of the office quickly when you know you'll be plugging back into the mains within a couple of days or so. Next is Hibernate, a bit slower but no power needed, OK for going away on holiday for a couple of weeks. Last is power off, the safest but slowest.

Also note, if you have classified information (secret or above) on your laptop - DO NOT SLEEP - you must either hibernate or power off. Otherwise, security information might be readable from memory.

One final point on "is it safe". It is normally safe. But, some computers do fail to resume reliably. This is mainly due to faulty graphics drivers. Always save before sleeping. Indeed, that is a standard to live by!

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But when I make my computer Sleep and completely power off. The next day I see everything are same like previous day. I didn't lose anything even i unplugged the power. –  Madan Sapkota Jan 21 '13 at 15:11
    
@MadanSapkota Windows 8 hibernates after about 3 hours of sleep –  Sathya Jan 21 '13 at 17:35
    
When you choose the Sleep option, the computer does not power off. Usually it shows you this by slowly blinking the power light. The battery in the laptop provides power when you unplug from the mains. However if you leave it unplugged and come back in a few days, you will find the battery drained and you will get a message from Windows telling you that you didn't close down properly. Or you may be lucky and the laptop will place itself into "Hibernate" mode which is a mix of the two modes that doesn't need power. –  Julian Knight Jan 21 '13 at 17:37
    
@Sathya: Are you sure? I think this depends on battery state and settings. Some laptops come with Hibernate disabled by default since it takes up a significant chunk of space (not really a problem these days, I think it is a user perspective thing). My laptops happily sleep for days, even the W8 one. I tend to leave them plugged in to the mains. I hardly ever power off. –  Julian Knight Jan 21 '13 at 17:51
    
@JulianKnight I haven't enabled hibernation or changed any plans, this is how the power plan is set on my fresh Windows 8 install i.imgur.com/FJPGmDM.png But you're right, on a fairly new laptop, the sleep mode can keep the memory state for a good 12 hours at least, subject to the battery state. –  Sathya Jan 21 '13 at 17:54

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