I have a couple XP dinosaurs I use here at work.
IMHO you can just ignore Microsoft warnings and keep XP.
I believe I was able to go to control panel, click on internet options, in the 'home page' window type in
Bing and when you click on the big E (now defunct Explorer) and it will take you to the Bing browser.
Or just install Linux, I had an old Vista computer I hated and one of the guys here walked my through a Mint (version of Linux), just put a install folder on a USB drive, reboot the computer and it auto installed, I was surfing the internet in minutes.
And Mint is waaaaay faster than any Microsoft OS.