I want to upgrade my cpu........?

Are you sure you need to upgrade the processor?

How much memory (RAM) do you have? This is usual a more important factor in higher end systems (2.80 Ghz is a pretty decent CPU).

u can run a dual core processor but u don't need upgrade... max ur memory out if u run 1.5 gig memory do this first it will be the biggest change in cpu that u will notice and go to intel.com and flash ur bios to up grade what u have..actually u don't need to get another processor just learn to upgrade what u have ...this way u can upgrade computer and the best thing about it is ...it is FREE....i like Free

reload the OS or delete the temporary files, uninstall unwanted programs stop unnecessary services , defragment all drives & add some more Ram if possibe run in dual channel mode only this can make system faster ......