Hi JM,
Although QuickBooks 2012/13 can in some cases install on Windows 8, its not offically supported and does not always work. Another thing to take note of is that QuickBooks 2012/13 will no long be supported as Reckon Tech Support only supports the last 2 versions released, and since Reckon Accounts 2014 is being released it will "Sunsett" the 2012/13 version (meaning Reckon will no longer support it).
You will have another problem with this, being your company file will not be able to revert back to the 2012/13 version if you have been using it in the 2013 version.
If using Windows 8 then I highly recomend upgrading to the 2014 version which is just now becoming available. At least this way you will be using a supported version in a supported environment, and if you need help tech support will be able to provide support. If you do go with QuickBooks 2012/13 on Windows 8 and run into problems you wont be able to get tech support, so upgrading is the safest course of action.
Here is a knowlege base article on QuickBooks 2012/13 & Windows 8 http://kb.reckon.com.au//issue_view.asp?ID=4693.
Hope this clarifies things for you.
Regards,Shane.