Old videos can be upscaled to almost crisp 4K quality through the use of video upscaling tools such as AVCLabs Video Enhancer AI. This software allows users to turn old videos into crispy 4K by using artificial intelligence algorithms to enhance the resolution of the video. The process involves installing and running the software, and then following the simple steps provided to upscale the video. It is important to note that before upscaling old videos, it is recommended to check the system requirements and ensure that the CPU or GPU is capable of upscaling videos with AI. Additionally, other tools and techniques such as detail preserving upscale and AI-based video enhancing software can also be used to upscale old videos to 4K.