The presence of a PC in the Eientei borders on impossible. The only place in Gensokyo where such a thing could be plausibly found is in the Scarlet Devil Mansion (probably running Windows 95 or 98 at the best) or Kourindou (where it would be unpurchased, and unpowered). Even if Kaguya (or her friends) bought a computer from there, there would be no way to power it.
But ignoring that, assuming they were able to find a power supply, they'd at the very least be unable to get an internet connection through the Hakurei Boundary. And considering that she encountered a hard drive failure, the most impossible thing of all of these, is for it to be serviced... in the Bamboo Forest... in Gensokyo.
Kaguya is immortal, so her suicide won't last. But nothing's bringing back that computer that shouldn't logically even be present, much less powered, much less connected to the internet.
Kaguya having a PC is plausible the Lunarians actually have more advanced technology then the outside human world.
It's a common misconception that Gensokyo is devoid of advanced technology just because many residents are troglodytes doesn't mean all are.
There's Rika,Chiyuri, and Yumemi in the PC98 games.
The Kappa also have fairly advanced technology including optical camouflage and know what nuclear power is. Hakurie boundary BTW is not exactly impenetrable and can be breached Yumemi,Yukari,the Lunarians,and likely the Kappa can cross it.
The place is probably best described as some sorta warp world where things from various eras and locations are just lumped together.
The_Specialist said: she commited suicide because of a bluescreen? if everyone did that, the world's population would shrink to almost 0.
It's a hard drive error. I'm going to go out on a limb here and say that Kaguya either couldn't or didn't bother to update the contents of her (likely enormous) hard drive.
