For complex reasons I need to purchase a computer that runs on XP. It also needs to have good graphics abilities. I would have thought that that would not be difficult, however, I am having a hard time. Can anyone point me to a website where I might purchase one?
A computer with XP? Online? On a Website?
You need to go to your local computer shop, they should be able to do just that for you or it is at least what I have to do for some specific customers needing to run WinXP for whatever the reason.
I work for the state. We can’t throw away computers since they were purchased with state money. Another state agency finds homes for them with other agencies, and sells some of them to the public.
ebay. Last time I checked (about a year ago), there were professionally-refurbished ones available cheap-ish.
Have you looked into using virtual machines? I run an XP virtual machine at work to handle software I need that won’t run on later versions of Windows.
Even though it is virtualized, the performance of the machine is pretty good. It actually outperforms the hardware XP machine it replaced. It’s doing compiler type stuff though which is computationally intensive but isn’t graphically intensive. I haven’t tested its graphical performance.
We’re about to dump close to a thousand very outdated XP boxes to get out from under the April sunset problem. The town has allocated zero funds to new computers for years and is balking at the price tag associated with the forced update. (Less than 20% are even Win7-capable, nor is there IT resources to do bare-metal rebuilds on a couple of hundred boxes.)
Point being, you should have your choice of XP computers from industry, education and government scrap heaps.
But will it play Doom? 
If you’re near a (big?) city, use CraigsList. I got my last 3 computers that way, and I work in IT. My current one is XP.
But…
Buy from someone that’s selling multiple computers, then you can exchange it if it doesn’t run. Make sure you can do this before you buy one.
And…
Make a full backup as soon as you get it running - when you buy used, you are the ‘system admin.’.
Then make another backup once all your programs are installed and configured.
You might have to upgrade the graphics yourself, but that’s easy to do, or the seller might do it for you.
Descent is better.
I never got off on Descent.
One of the few good things about my ex Wife was co-op Doom I&II with the M-16 patch.
Try any small computer hardware supply store. Several near me are selling used surplus machines for cheap.
I buy fanless PC’s from Stealth computers, and they will still sell them with XP (they ship with a Window’s 7 DVD, and use the 7 license which functions as a downgrade to XP).
That is some serious cash.