If you have a genuine Microsoft Office 2007 installation disc or a digital backup, and most importantly, a valid , you can legally reinstall it.
You can use a lightweight version of Word for free in your web browser. It’s official, safe, and always up to date. microsoft office word 2007 free download
If you want the desktop feel, you can buy Office 2021 (Home & Student) for a one-time fee of roughly $150. It looks different from 2007, but the learning curve is minor. If you have a genuine Microsoft Office 2007