The Knowhow
First checks:
- If you are using a USB keyboard or mouse, ensure they are still functioning and the adapter hasn't become disconnected. Check the batteries to make sure they still have power
- If you are using a laptop, connect it to the mains; the battery may be too low on power to restart
- Check for a sleep button on your keyboard (This often has a "moon" or "zzz" symbol on it). You may need to press this to awaken your system
- Some systems require you to press the power button to wake the computer. Please check your user guide before doing this
If you are using a laptop, connect it to the mains; the battery may be too low on power to restart
Check for a sleep button on your keyboard (This often has a "moon" or "zzz" symbol on it). You may need to press this to awaken your system
Some systems require you to press the power button to wake the computer. Please check your user guide before doing this
Extra solutions for laptop users
Laptops are more prone to this problem than desktops for a number of reasons.
If your computer goes into sleep mode when the screen is closed but won't wake up when you reopen it, a switch may be stuck. Some laptops detect whether the screen is open by a small switch at the back of the machine near the hinges.
Carefully check the back edge of your system looking for this switch. If it's blocked due to dust or other debris you may be able to free it with a small blast of compressed air. If the switch has become lodged in position, gently press it with an unfolded paperclip to align it properly again. Using a cotton bud dipped in screen cleaner, gently remove any dirt and sticky material from around the area, then wipe clean.
Many users also find the following procedure fixes the problem:
- Disconnect the mains power
- Remove the laptop's battery
- Hold down the power button for 30 seconds until the system turns off
- Wait one minute
- Insert the battery again
- Connect mains power
- Restart the computer
This method ensures all your system's components are free of power so the computer should boot cleanly again.
Check your system's current power saving options if your system is entering sleep mode when you don't want it to. For more information on this, click here:
Calibrating your notebook or netbook battery in Windows 7
General sleep and hibernation mode fixes
- Make sure your computer's operating system has all the latest updates and patches
For advice on updating Windows, click here: Windows Updates
For advice on updating a Mac, click here: Mac Update
- Check that you have the latest BIOS drivers; older versions can have issues with sleep and hibernation modes
You should be able to download the latest BIOS drivers from your system manufacturer's website. Please check the computer's instruction book for more details.
- Clean your computer thoroughly, inside and out. Use a can of compressed air to remove any dust inside, especially around fans and ventilation systems
For more information, please follow this link: Cleaning dust and dirt off your computer
If the problem keeps occurring, we advise you to get your system looked at by a repair specialist; this may be a software or hardware fault.



