There is no definitive "fastest" way to reinstall Windows, as many different factors can influence the speed of this process. Some potential options for speeding up a Windows reinstallation include using a bootable USB drive or CD to install the operating device rather than performing a standard installation from within Windows. Additionally, you may want to disable certain system services or processes that are not essential for standard functionality to reduce the time required for installation. Ultimately, the best way to reinstall Windows quickly will depend on your specific configuration and needs, so it may be advisable to experiment with different methods to find the one that works best for you.