Computer Rigs with i3 , i5 and 17 processors ?

I have an old desktop system. I have seen lots of gaming console, but what fancies me the not is to make a gaming computer system. Let me tell about my system's configuration. I have an old Intel Celeron, 80 GB PATA Hard disk and 256 MB of RAM , I cannot play any other game except the games that are implicitly the part of my windows xp operating system. I have got bored of playing that Solitaire card game and now want to be a game freak , but I do not want to play games on joystick , I rather prefer keyboard to play games , can you guide my what sould I possibly do to turn my pc into an hardcore gaming pc that can support modern warfare and sports related games with high definition graphics and display. I am ready to sell this desktop and but a new system . But please tell me about the price as well , in how much I can sell my desktop and get the new one. Please give maximum replies as you can as I cannot wait any more to get myself involved in such interesting games.

I do not think you should embarrass yourself and the buyer by telling to sell that computer system. You cannot even think of installing even a shortcut file or a patch file of the games you were talking in your system , even it may set your desktop ablaze because of huge amount of pressure. I think you should purchase a whole new system rather than making any up gradation and specially think of the processor you are going to buy, If you really want to assemble a gaming pc then you should consider the AMD processors rather than installing intel processors. You can turn your into a gaming rig but I do not know how to do it as I am not that gaming freak.

Thankfully I am going to sell my old system to one of a school student in 2k , who needed a comuter system for school project work and to work on small applications such as excel sheets. I was considering the Core i3, i5 or i7 processors to assemble a Computer rig rather than going for AMD procesors because of their overheating issues. I do not further spend on buying extra cooling fan and the coolant for the processor . I had forgot to mention about the monitor, please tell me should I sell it or still I can play games on it before that boy approaches me to takeover the system
P.S I have a Samsung Sync Master CRT monitor.

You are very lucky that you sold that thing which you were saying is a computer system in 2000 bucks. I will not be surprised if that student who is buying the system from you comes back after some days with lots of issues. Jokes apart , you will be able to play games on that system, but you will not enjoy it at it will have limited graphic support and the feel will be missing. So it would be better to buy a new monitor and sell that CRT monitor. Get a Samsung SyncMaster BI930 19 inch LCD Monitor , will cost you 8000 more.
Cire i3 processor would be enough as it has brilliant GPU support.

A gaming computer is also called some times a gaming rig, is almost similar to a conventional pc or a normal pc but the difference lies in few peripherals mostly a video card that are specially performance games . These rigs are typically designed such that they can support high definition graphics and play the most demanding games of today's world. The manufacturers have to set the gaming as the benchmark and design accordingly the whole system. They try their level best to maximize the the performance and display. These gaming rigs are manufactured in low end systems , some are mid range systems and the res of the gaming rigs support high end gaming . These systems are very costly as compared to the mainframe, because they need high graphical support.

It is pretty obvious because of the need of high graphical support , the manufacturers of graphical cards earn a large amount of revenue form all the three categories of the gaming rigs. You can opt any of the core i processsors , i7 is the most costly of all the three processors , it will cost you just around 15000 and the tax aboove just for the processor, the i3 and 15 are a bit lesser in cost than i7.You can even directly buy system fom Alienware, Vodoo Gaming pc Origin PC. These manufacuterers have their expertise in manufacturing gaming systems but the cost is will attract your most attention .