Will open the case and double check but think it's a 500w one but 3 yrs old.
Not really bothered about new new games just yet, as will get a new motherboard and processor at a later date, when I can afford them, but just bought a new 24" monitor, upgraded to Windows 7, and although the 9600gt runs ok at 1920x1080 (and was good at 1680x1050 which I played at before) for the games I play WoW, BFBC2, Civilization etc, I have noticed a drop in fps and read an upgrade to the gfx would make quite a difference.
Give us the brand and model of the PSU. Unless it is quite poor(possible) it should handle the HD5850. That card is close to 3 times faster than your 9600GT BTW.
Your motherboard can handle much better processors but even something rather cheap would be a decent upgrade especially if you are willing to overclock. http://www.aria.co.uk/SuperSpecials/Other+products/Inte...
That would give you twice as much cache and a .6 ghz boost which would help a lot and it can OC much higher. It's a nice deal and with the HD5850 would come in under your budget if you PSU ends up being able to handle the card.
Yeah the psu will be fine, get the 6870 graphics card, I dont know where your buying from but where I am looking its only £10 more expensive so its worth it.
A cpu is easy to install. Take the old heatsink off, remove the old cpu, usually has a little clip holding it down, when installing the new one there will be a small golden arrow at one corner of the cpu, it must align with the arrow on the cpu socket. Push the clip down, clean old thermal paste off the heatsink with some alcohol solution, reapply some good quality thermal grease to the cpu and replace heat sink. done. takes less than 10 mins
That is weird. If the computer wasn't detecting any video it wouldn't start up so the computer itself is seeing the card...
You may just have gotten a defective unit, it happens. This soon after purchasing you should probably return it to the retailer but I guess seeing if XFX has any ideas first makes sense.