Some of the new features included in Windows 7 are advancements in touch, speech, and handwriting recognition, support for virtual hard disks, support for additional file formats, improved performance on multi-core processors, improved boot performance, and kernel improvements.Windows 7 retains the Windows Aero user interface and visual style first introduced with its predecessor, Windows Vista, but many areas have seen enhancements.Support for themes has been extended in Windows 7. In addition to setting the colors of the window chrome, desktop background, desktop icons, mouse pointers and sound schemes, themes in Windows 7 include desktop slideshow settings. A new control panel interface, accessible through the "Personalize" context menu item on the desktop, has been introduced which provides the ability to customize and switch between themes, as well as download more themes from Microsoft's web site. Support for "theme packs" is included; theme packs are cabinet files with an extension of .themepack, and consist of a .theme as well as any number of image, sound, icon, and mouse cursor files. Windows 7 recognizes this file format and will switch the user's theme to the theme contained inside when opened. A Windows 7 theme can also specify an RSS feed from which new desktop background images can be downloaded.