TL;DR: The race to 1GHz was very much a real thing at the turn of the century. It was quite entertaining as well, coming down to a photo finish between AMD and Intel (the former took the win by mere days). Fast forward to today and you won't be able to find a new desktop CPU with a clock speed under 1.6GHz or so. But, you can underclock an existing chip to run much slower and that's exactly what NTDEV did in his latest video.
Forward-looking: Windows 7 will exit extended support very soon, but "micropatches" offered by 0patch are ready to take Microsoft's place in keeping the old operating systems safe and sound against Internet threats. At least for the most dangerous flaws discovered in modern Windows versions.