johneastham :
hi thx for the reply's my model is the pentium e5700 and i am upgrading from a hd 5450 and if it helps i have a budget of around £200 my resolution is 1600x900 and i play grand theft auto, borderlands, nfs shift etc and i use windows 7 home premium with 8gb ram
the pentium dual core is a different story altogether.
whereas pentium has one core,or one core with HT,pentium dual core has two physical cores.
the e5700 is pretty decent,not ideal but decent still for gaming.
since you said £ I'm assuming your in the UK.
I'd recommend the gtx 580
http://www.scan.co.uk/products/1536mb-evga-gtx-580-refurbished-40nm-4008mhz-gddr5-gpu-772mhz-shader-1544mhz-512-cores-mini-hdmi-2x-
although for 1600x900 it's probably overkill