I feel sorry for you Upendra09, your computer is really old, the guys are right tho in what they say, theres really no point in upgrading that CPU or anything on that PC, you would be better just saving up your money and buying a new PC in the future later in the year or when you can afford it, and when that time comes make sure you come back here, tell us what your budget is and someone for sure here will give you advice on a full system within your budget.