By "chip", I presume you mean processor. I doubt very much that you'll be able to use the Pentium 4 processor in your aging computer. You really should have researched this before buying a processor. But, I can tell you it's highly unlikely you can use it; you would need a newer motherboard to support the Pentium IV. And, upgrading motherboards in systems with proprietary components, which is often the case with the major computer brands, is a shakey proposition. Standard motherboards may not fit in the computer case. And, the computer may have a proprietary power supply that won't work with a standard ATX or microATX motherboard due to non-standard power connectors on your power supply. Also, the power supply simply may not be adequate for a more powerful system.
If you're not prepared to basically build a new system yourself and you still have the option to return that processor, I think you should return it.
