Over 20 years ago, they would tell you if you were using a "Fast" computer the microscope puzzle would be impossible. Back then "Fast" meant 200 mhz, a tiny fraction of modern computer speeds.
You can still find walkthroughs that tell you this, because the original walkthrough was written over 25 years ago, back around 1995 when a 200 mhz computer was a fast, top-of-the-line computer.
If you try to play the game using the original game exe on a 64-bit computer, the game will not run at all because it is a DOS game and DOS is a 16-bit operating system. 64-bit operating systems will not handle 16-bit programs outside of emulation.
Modern download versions of 7th Guest are configured to use either DOSBox or ScummVM.
With DOSBox what the game sees as the processor can be slowed down with Ctrl-F11 and sped back up with Ctrl-F12.
https://www.dosbox.com/DOSBoxManual.html#SpeedHelpMost current preconfigured versions of 7th Guest don't even use DOSBox anymore.
They use ScummVM.
Games that use ScummVM don't use the original game exe at all. They replace the original game exe with the ScummVM exe, which won't be speed sensitive. I have no idea whether or not the ScummVM exe works well with the Microscope puzzle (also called the Germ-eat-germ puzzle and various other names), but if it doesn't, it isn't because of the speed of the computer. ScummVM is made to work on modern computers.
The only time the "Fast computer" problem might be relevant is if you're using a vintage computer from the 1990's with the original disc version of the game that was made for DOS.