What do I need to speed up my Pc/ How Do I install it...?

You're actually looking for a new computer.

Celerons are horrible and in order to upgrade a chip that old you will probably need a Motherboard as well check the bundle kits on tiger direct or combo deals on newegg it would be best to do your research before commiting and asking someone face to face

Upgrading it would be a waste of cash, save up some cash and get a completely new setup.

Am I looking for RAM is it? >>your pc is 5 years old, So it is less use add ram, and when you add a new ram, pc always crash, my pc is same to your, and the ddr2 ram is very expensive. Or a better processor? >>if you change processoer, you have to change main board. it no need. and it is enough. Question What do I need to speed up my Pc/ How Do I install it...? I'm not a computer newbie or anything but what are the exact components I need to speed up my pc for running games/ multiple applications fast... Am I looking for RAM is it? Or a better processor? This is my current PC details: Intel (R) Celeron(R) CPU 2.66GHz 2.66GHz, 504mb of RAM Clean your Registry can make your computer faster Microsoft Registry Problems = Slow Computer! The Windows registry, Containing information and settings for all the hardware, software, users, and preferences of your computer, whenever you make a change to the Control Panel settings, file associations, system policies, or installed software, the changes are reflected and stored in the registry. When the Windows registry becomes very large, your computer’s can become very slow and it can cause it to be unstable. http://top5registrycleanerreviews.com

You can use a registry cleaner to clean up your computer and then make your computer faster,Why?the reason is that there may be some registry errors and remnant,corrupt files and temp files in your computer to cause "computer slow". Every time you install and uninstall software on your computer and surfing online you create junk in the computer registry.over time, the registry can grow to enormous proportions, especially if the various programs you've installed do not do a good job of deleting and/or updating it's Registry entries.You need to scan and clean your computer with registry cleaner to make it fast.Good Registry Cleaner will improve your computer and Internet performance dramatically! There are some comparison and review of TOP 5 registry cleaners. http://www.speed-up-my-computer.com You can download and scan your computer for free.

If it's five years old, I'd suggest just buying the components and building a brand new one. It really doesn't cost all that much to build a suitable gaming PC. Check out the link below for some ideas. http://www.extremetech.com/article2/0%2C2845%2C2346481%2C00.asp