Even if an upgrade is possible, the money is better spent toward a new computer. Microsoft says many PC makers are offering deals timed to XP's retirement.
Be aware that either way, you may also need to buy new software, as older versions might not run on Windows 7 or 8. Microsoft, for instance, is also ending support for Office 2003 on Tuesday.
Q. My XP computer works fine and fits my needs —and I don't want to spend money on an upgrade or a new machine. What should I do?
A. If despite the warnings, you are still running XP, here are a few things to do:
First, be sure to run all of Microsoft's previously released updates, plus the last one on Tuesday.
Then think about what you really need the computer for. If you don't need an Internet connection, unplug it. That will minimize the risk. Be careful about attaching USB storage drives, as that might introduce malicious software.
If you need the Internet, refrain from using email, Facebook and other communications channels through which malicious software might travel. Use a tablet, phone or another computer instead.
It's also a good idea to lock down your computer by using a profile that lacks administrative rights. That will make it harder to install anything new, including malicious software.
Gartner fellow Neil MacDonald says XP computers on corporate networks have more options, including using XP only for crucial software that won't run on more up-to-date systems and accessing a virtual desktop remotely for email, Web and other modern tasks. He says companies can also pay Microsoft for customized fixes beyond Tuesday, but that gets expensive.
Q. Why is Microsoft doing this?
A. As technology improves, it makes less sense to support something designed a PC generation or two ago. The company's resources are better spent on making newer products better.