The problem sticking with Windows is that at a security point, older versions become less and less secure, opening a door for attackers and phishing and viruses and whatnot to those who aren't tech savvy.
I would personally load Mint on that older laptop or any other lightweight Linux distro. Mint looks and performs quite similar to Windows. It's install manager is similar to the Windows Store.
but of course saving money is also nice!
Best part about Mint and most Linux distros is that it is 100% free!