I only check this forum from time to time so sorry for the late reply. If you installed Office from a DVD, do you still have that DVD? I am assuming that you don't have it or you wouldn't be asking the question. If it came pre-installed on your old PC, I'm afraid you're out of luck. But you can get a copy of Office 2016 cheap on eBay, Bonanza, Facebook marketplace, etc. because it is now obsolete. (Although I use it as well and have no intention of upgrading.) Make sure you also get a valid install key with it.

If you install and older verision of Office desktop, be sure to completely uninstall 365. Don't use the Windows uninstall feature. It would be better to use Revo to completely get rid of it. The free version works fine for me. Good luck.