The process takes even longer if you have a fragmented or nearly filled hard drive. The biggest updates, released in the spring and fall of every year, take upwards of four hours to install - if there are no problems. Windows 10 updates take a while to complete because Microsoft is constantly adding larger files and features to them. Unfortunately, downloading the necessary files can take ages if you don’t know how to optimize everything. All Windows 10 updates come with security fixes, exciting new features, and other assorted improvements, so it’s critical that you install them as soon as they become available.