I’m pretty sure that a Celeron D is a 64 bit processor. Did we get confirmation on that?
https://support.hp.com/us-en/document/c00683794
Celeron 352 (C) 3.2 GHz
physical address extension 32 bit
instruction set 64 bit
greek to me
They have 64 bit timelines here; https://en.wikipedia.org/wiki/64-bit_computing
Looks like mid 2000s was the beginning of the changeover for PCs. MS had a 64 bit XP but cancelled it in 2005 due to lack of PCs running 64 bit processors.