Ok, analizing, here we go:
Your "AMD Phenom(tm) 9600 Quad-Core" is from 2007/08, a bit old and for today's performance 95W is quite energy-hungry, but still, it is a good quad-core with 4? 512 KB L2 Cache and 2048 KB L3 cache, running @ 2,3 GHz which is MORE than enough for BF2/PR.
On the memory (RAM): 4 GB is not really much anymore today (usually at least 6, but most common today is 8 GB), but worst is, that your RAM (even though 4 GB should be just enough/fine for PR even on max. graphics-settings) is only 667 MHz RAM, seems to be quite "old" DDR2 RAM (todays DDR3 standard, which is there already for quite some years now, is running 1333 MHz at least, common is though 1600 MHz, like mine.)
Your 667 MHz-RAM also makes me believe your motherboard (ASUS) is quite old, and only supports DDR2 RAM... (and yes, just found out, only DDR2 RAM support:
https://www.asus.com/Motherboards/M2N68AM/#overview quote: "2 x240-pin DIMM, Max. 4 GB, DDR2 1066/800/667/533 ECC,Non-ECC,Un-buffered Memory
Dual Channel memory architecture
*DDR2 1066 is supported by AM2+ CPU only")
You could go to a DDR2 1066 RAM, but main-problem is the limit of 4 GB on the motherboard... so if you can afford it anytime, a motherboard upgrade is wise, with 8 GB RAM being best.

)
Ok, for the GPU, the GTS 250 is mid-range (and from the year 2009...), in between performance of todays GeForce GT 640 (quite low end) and the better Geforce GTS 450, but in general, your GPU is as good as the best GT 640 and performance wise a bit less powerful then the also old GTX 260 (from 2008, which was almost high-end back then).
So, if you can afford it (dunno what your status is), you could enjoy PR as it's best with a new ~ 180 $ quad-core from Intel's i5 class, a quite cheap GTX 660 or 760 (those are great and still good-price GPU!!) and some 8 GB DDR3 standard (for example running 1600 MHz. Btw. there are already motherboards today which support the new DDR4 standard!!

But of course those are still too expensive for everyone, including me of course, I am not rich either...

)
And if you want to go cheap, buy a AMD quad-core, AMD graphics card, OR, directly an a new mainstream "Kaveri" quad-core from AMD, where the graphics are INTEGRATED IN THE CPU!!

So no graphics card needed then for you, THAT would be the REAL cheap solution.
