Restore wallet.dat on windows 8
Windows 8 is just like Windows 7. 

But on a mondern bitcoin-core installation you will be asked where to put your data-directory. So if you changed the default path you need to consider that.

So if you found your data directory, your wallet.dat file is right there. Make a backup or restore it as you wish.

There is also a good tutorial video around for more visual explanation.

For a more detailed explanation on what steps are required to restoring your wallet.dat you can check out this post.