This was a computer my dad used for work in the late 90s and later shelved, where I would sometimes find it and play around with it.

Here's what I remember about it. And yes this memory is accurate.

Micron Millennia (definitely a Millennia. Not some other model)
Desktop form factor (horizontal)
Pentium II (not III, or MMX, or original Pentium, definitely a II)
Windows 95 installed (the version that says "Microsoft Internet Explorer" on the boot screen)

This tracks with when the machine was most likely purchased, which would have been around 1997.

It was unfortunately thrown away at one point. Not by me.

I cannot find any evidence of Micron ever making a Millennia that fits all of these criteria. There are some very similar models that you can find, but they never seem to have a Pentium II, or if they do, it's a different model, like a ClientPro.