Celeron PC

Is it possible to boot and run DietPi on a generic PC that does not have an image made for it? I have a celeron pc that I would like to run DietPi on. What image would I use? Any special instructions?

Yes, but not native due to vast number of possible hardware combinations that we cannot support. We offer a virtual machine image:
https://dietpi.com/forum/t/dietpi-for-vmware-virtual-machine/83/1