Possible Solution(s):

1. Go into control panel, (Start > Settings > Control Panel)
2. Once in, click the Power Options Icon
3. Make sure the Power Scheme is set to Always On
4. Make sure the Turn Off Monitor and Turn Off Hard disk etc… are set to Never
5. Go into the Advanced tab and change When I Press The Power Button on my Computer to the value Power Off (its probably set to hibernate or something like that)
6. If there iss a Hibernate tab click this, and remove the tick from Enabled Hibernate Support
7. Click on the OK button at the bottom of power options!

That might work, there's another way of enabling / disabling fast shutdown but for the life of me can't remember where it is