Office 2013

After upgrading to windows 10 and finding they didn't work well together, I lost a lot of stuff.  The one thing I can't get back is the pre-installed Office Home and Student 2013 which came on my PC to be activated.  Now I need to reinstall it because I can't find it on my system anymore.  There is no option to reinstall on the Windows store page and when I enter my activation code, it tries to download the 32 bit version which won't work.  The 64 bit version won't seem download and properly run either.  I really need some help on this but no one seems to know the answer to how to get this back.