Yeah, I agree with Effeectt on this one. You can use the power sipping (60W) GTX 750 Ti or an R9 265X (110W) with a new power supply, but the system you're talking about is at least 7 years old. Keep in mind that all (or at least almost all) Pentium 4 CPUs only have 1 physical core and one thread, and they were the top of the line during their time. For measure, a typical Core i7 from today has four much stronger physical cores and 8 threads (the 8 threads effectively make it an 8 core CPU), so you can see how much of a disservice such an old computer would do to even the slowest modern graphics cards. It's best you get a new system.