You are going to be trapped in a room for 12 hours with a mid 2000s office desktop with no internet connection and an external hard drive; what are you putting on the hard drive?
I've got some DOOM WADs I have been meaning to play so I would probably grab Trench Foot, Total Chaos, and the sequel to Ashes 2063, Ashes: Afterglow with a portable install of GZDoom to play them.
After that I'd probably bring Star Trek TOS and a MOBI copy of Neuromancer by William Gibson combined with a portable install of VLC and Calibre in case the computer didn't have applications that support the file format.
What about you?
I wanted to phrase this in a way where it isn't a prolonged or desert island style question where the responsible idea would be to bring Wikipedia ZIMs and educational PDFs. It's just an awkward amount of time to kill. The mid 2000s office desktop stipulation is just an additional challenge so you can't just bring in a copy of Baldur's Gate 3 or Cyberpunk 2077.
Edit: By mid 2000s I meant around 2005; the XP or Vista.
I bought it, but I only have about 9 hours into it so I'm no expert on it, still getting used to it really, part of that "play time" is idle as I do other things while it's in the background.
I haven't played that one much, but it's a lot like ProWrestling Sim. It's a management sim, so a lot of menus and text. You recruit wrestlers, setup the various faces/heels/tag teams/stables, you schedule the storylines, rivalries and matches, etc... It's very deep and addictive, if you like the genre/subject matter.