Windows 7 What Browsers will still work with Windows 7?

I have a neighbor who has an old HP desktop he wants to give to his 10-year-old Grandson to get him started on computers.

I set the computer back to out-of-the-box settings and cloned the disk to an SSD. 

The problem I am having is finding a browser that still works on Windows 7. I have downloaded and burned to CD several that said they would work, but don't.

Are there really one that still works on a 7 computer? 

I saw a couple that said will work, but needs Windows 7 with SP1, which is not available any longer.

I see Windows 10 programs are still available, but I don't know if he wants to spend the $$$.

Any advice would be greatly appreciated.

Thank you.