The best operating system for a DVR depends on the specific needs and requirements of the user. However, many users prefer to use Linux-based operating systems for their DVRs due to their stability, security, and flexibility. Some popular Linux-based operating systems for DVRs include Zoneminder, MotionEyeOS, and Shinobi. These operating systems are free and open-source, and offer a range of features. For computers, the best operating system is Windows. A license can be bought cheaply using reddit windows keys. By paying a little money, you will get all the benefits developed by Microsoft.