How old were you when you first installed computer hardware yourself?

do you mean hardware as in something external that you plug in, or an internal part, like RAM?

and if the former, does a USB flash drive count, because technically, that is hardware, and although there are "autodrivers" to accomodate that now, back when i had Windows 98, 1st Edition, it did not come with them built-in, and i had to find a website that had them (this was before Google existed, too).

if you were referring to the latter option, inside the PC, i didn't take that on till i was 19, and owned my own PC, which i bought used from the neighbors, with the paycheck from my first job. after playing around on the computer for a day or so, i had the whole PC torn down to it's tiniest part, before subsequently reassembling it fully. i had never done this before (nor had i any formal training on it), but it started up again after!

if that doesn't count, then probably it would be the following year when i built my own PC.

rofl.  personal computers hadn't been invented yet when I was 12 -- not even the Heathkit build it yourself models.

In my early 20s, but that's because there was no such thing as home, or office, computers when I was younger.  You're idiotic questions makes it obvious that YOU give no account for peoples ages or what equipment was available to them.

Never heard of it

Maybe 15 when I installed a modem just to pirate games from other people through a BBS.