Windows 7 was primarily intended to be an incremental upgrade to the operating system, intending to address criticisms faced by its predecessor, Windows Vista (such as performance improvements), whilst maintaining compatibility with hardware and software designed for Vista. Windows 7 Service Pack 1 (SP1) is an important update that includes previously released security, performance, and stability updates for Windows 7. SP1 also includes new improvements to features and services in Windows 7, such as improved reliability when connecting to HDMI audio devices, printing using the XPS Viewer, and restoring previous folders in Windows Explorer after restarting.