Hi:
It depends on what the specs for your specific model PC indicate.
There is normally a list of included software on the specs page.
Usually the preinstalled versions of MS Office are trial versions, and only work for a certain period of time--generally 30 days.
I recently purchased a HP 255 G7 business-class notebook that came with Office 365 pre-installed.
This was a trial version. No product key was provided.
I uninstalled the software, and installed a full version of Office 2007 Standard, which is fine for my needs.
If you would like free Office-type software that allows you to view and edit Microsoft Office Word and Excel files, you may want to use the free Libre Office software which looks and works very much the same as MS Office.
https://www.libreoffice.org/download/download/