Searching files and file content in Window seems an easy task: you fill the search textbox of a file explorer window with the content you need to search and Windows start searching. But I have to say I don’t feel comfortable searching files in this way, and this function lacks some options like, for example, preview and searching using regular expressions.
So for this task I prefer to use a free tool named Agent Ransack which you can download at this url:
https://www.mythicsoft.com/agentransack/download/
Agent Ransack is easy to use, fast, has plenty of options, and is free for personal and commercial use.
I suggest you to give it a try.
See you soon!