|I was under the impression that these were socket 775 and your P4 is socket 478, but I just double checked and there are Celeron D processors for the 478 socket (per intel), BUT that does NOT mean that your motherboard will support it!!! Since you have not chosen to list your board, you will need to look for the CPU support list for your board to find out IF it will work. It is VERY unlikely that this processor will your on your board since you have one of the 400MHz P4's, your board will not run the 533FSB. The best you probably could run is a P4/400/2.6GHz if you can find it cheap enough.|
Don't waste too much money on a system that old... You will get more out of it with an upgrade in processor, video card, and maxing out your memory, but not enough to be happy for very long. Save the money and look for or look to build a new system with a Core 2 Duo or better, one of the newer i3-series processors.
You have to be a little bit crazy to keep you from going insane.
This site is about helping people, lets keep it that way.