I am sorry to bother you with something simple but I can't seem to find the right info. I have an HP Pavilion 533W that is running a 1.79GHZ processor, I have not removed it, only looked for the specs.. I have an Intel Celeron D 2.53 GHZ /256/533 that I bought new for a similar model but the motherboard ended up bad. I would like to upgrade with this extra processor I have but I can't find enough info on these to find out if it will work. I am almost down to just having to uninstall it and compare the cpu's. I was hoping that someone would know the answer since this is not my strong point in the computer business. Thanks in advance for any help.