Gaming is probably one of the most power-intensive applications. If you get a machine that can run modern high-graphic games, it’ll run almost anything else.

A laptop is nice nowadays. Works as a desk machine, but you can still take it places. Get Windows 7, 64 bit. The gaming engines still offer it.

Start here. The designs are a bit twee, but they work and it’s a well-known brand. Note that the base model is probably all you need, and it’s about half your target price.

I would upgrade Windows 7 Home to Premium or Ultimate, but that’s not essential.

Your emphasis on graphics parallels a major trend toward high-powered video subsystems. In previous eras the amount of main system memory might have an impact on graphic performance because it was shared to save money, but nowadays it’s not unusual to find a graphic card with as much on-board memory as the main system. And they have their own CPUs (“GPU”, graphics processing unit) optimized for graphics (well, actually optimized for math, with the interesting consequence that video cards are the platform of choice for bitcoin mining). A good video card aimed at gamers or graphic professionals might go for around $200, but there are insane gamers who are proud to pay $700 for top-of-the-line bragging rights.

The video cards are why I’m not emphasizing main memory or raw CPU power. She should be comfortable with 4GB, though 8GB won’t be significantly more expensive. Also, as far as I’m concerned, there’s no longer any risk buying AMD instead of Intel, so don’t overlook the usually-less-expensive AMD systems.

Other changes in the last ten years include standard WiFi alongside a wired network connection, lots of USB 3 ports (and a concomitant elimination of all those old serial and parallel and keyboard and mouse specialized connectors). Floppy drives are gone, writable DVD is standard, but bluray hasn’t really taken hold as standard equipment. I bought a bluray r/w drive for about $100. A new hard drive connection technology called SATA is standard, and it’s used by bluray as well as magnetic hard drives. There’s also an external version of SATA that gives you a highspeed connection to an external drive; good to have to preserve that option for backup.

A lot of people would say that you’re blessed to still be using Windows XP, so you might want to be careful about timing your purchase around Microsoft’s next release. We’re between the lamentable Windows 8 and a rumored Windows 9, and widespread resistance to 8 has kept Windows 7 alive and well. You really should try out both Windows 7 and Windows 8 systems. There’s an inexplicably vast gulf between them, almost as if Microsoft had deliberately set out to disorient and alienate as many users as possible.

Me, I’d rather switch to Linux for everything than be forced to use Windows 8. I wish Microsoft would just stop. Everything. Just go away.

Speaking of backup, hard drives are so big now that old tech like tape is no longer feasible. About the only thing capable of backing up a hard drive is another hard drive. Look for systems that couple two or more hard drives in a “RAID” configuration, which provides redundancy and error correction. Or pick up a 3 terabyte external hard drive made for the purpose for under $200; external drives using SATA will be much faster than drives using USB.

You should be able to get a top-of-the line system for $2700, and that budget allows for some frills. Solid state hard drives cost twice as much as conventional mechanical drives, but man, it’ll make your hair stand up to see how fast a system boots from an SSD. And solid state will be more reliable and last longer.

Don’t settle for a display smaller than HDTV 1920×1080, and you might want to look into the latest superHD standard of 3840×2160–double the resolution. A 27″ flat panel might sound big, but because it’s wider, it’s not really that large; check out the prices on larger panels, 40″ or so.

I’m running out of ideas, but I’ve already dumped my usual verbose post, so time to wrap it up.

You may not like the brand but you will learn a lot about what is available in high performance boxes and a general idea of what they will cost.

For example:

http://www.dell.com/us/p/xps-27-2720-aio/pd?oc=fdcwlp1397&model_id=xps-27-2720-aio

4th Generation Intel® Core™ i7 Processor
Windows 8.1
16GB Memory
2TB Hard Drive + 32GB Solid State Drive
Touch EnabledTouch Enabled

$2500 and up