After April 11th, Windows will no longer support Windows Vista and Internet Explorer 9. This means there will be no further security patches, bug fixes or technical help for those versions of these products.
Fortunately, Vista’s bad reputation led most people to abandon it years ago. Some estimates put its current marketshare among all desktop computer operating systems at less than one percent. By contrast, Windows 7, which Microsoft scrambled to released two years after Vista in 2009, is currently the most popular operating system in the world, used on roughly half of all personal computers. In fact, Vista never gained huge market share to begin with; many Microsoft customers opted to stick with the pleasing and reliable Windows XP for years.
If you are a Windows user and you happen to still be on Vista, be sure to upgrade.