Text finder for Windows 11 on PC

[SequentialAnalyst]

I have zillions of files, going back decades in some cases. I want to search them using particular words or phrases, so I can get them in some sort of order, and delete what I don't want. The names and file structure are not very systematic, so I think I need a text finder. Then I can do some proper housekeeping on them!

I've got as far as googling, and found some possibles, but am a bit bemused. So I thought I'd ask on here. Does anyone use such a thing? Any recommendations?