Ed,
While you will eventually have to upgrade to a newer version of Windows, Your computer will not die because Microsoft stopped supporting Windows XP. Your computer will continue to run you just will no longer get any updates, patches, or service packs...but sometimes that's a good thing? :grin: Sometimes Microsoft updates mess up things on your PC that were working fine before.
Save your money and face the fact that you will have to update your operating system. If your computer is that old, you might look at upgrading to a new PC and get all the latest technology along with an upgraded operating system.
Window-7 has been reliable and is a good choice if you want to save money and just upgrade the operating system. Windows-8 appears to be pretty good, but may not be worth the price on an old PC since the old hardware cannot take advantage of the new features in Windows-8. Also, there is a much bigger learning curve with Windows-8 than with previous versions of Windows since Windows-95.
I have a version of Windows-8 that bought over a year ago and never installed it. My plan was to install it on my NetBook PC and see how I liked it before I switched over to my main PC. The main feature of Windows-8 is that it supports touch-screens so if you have a touch screen, it can function a bit like a tablet PC...but have the option to use a mouse or tap the screen.
....Rich