Looking for advice to investigate old virus riddled pc towers from parents storage

Hello all! I am helping my parents move and for the umpteenth time we have come across a pair of PC towers circa 2005-10. They became infected with unknown viruses - I had left home by the time these were decommissioned so I don’t know the state of the way they ran. But I used Kazaa and limewire on one of them at least.

I don’t have any cables or cords to power them on or plug in a monitor. I don’t want to send in the towers, but am thinking it’d be easier to disconnect the harddrives myself and safe boot to view/ retrieve lost family photos?

Problem is I have never done anything like that and this is part f my research into that angle. I run Apple now, and these are Windows XP probably?

How would you approach, and what am I overlooking? I have data recovery software in my Mac, but want to be as careful as possible before and up to that point. Would a windows xp virus from 20 years ago even affect my modern system?

Thanks in advance