Occasionally, you may want to find out the serial number you have used to install Microsoft Office. There is no easy way to find this, other than using 3rd party tools. You can, however, view the last five digits. This is often all you need to tie the installation to a particular licence or product card. Microsoft include a handy script that just does this. Just run:
cscript “C:\Program Files\Microsoft Office\Office15\OSPP.VBS” /dstatus
This is for Office 2013. For Office 2010 replace the Office15 with Office14. You can also run it from the 32-bit install path (Program Files (x86)).