Starting on July 12th, Microsoft will no longer support Vista SP1. Vista SP2, on the other hand, will retain support.
As a consequence of Windows Vista SP1 not being supported, it will no longer receive security updates making it a very unstable option for consumers and businesses.
Vista itself makes up an increasingly small of the world computer market: it now powers under 10% of the world’s PCs.
Now, according to NeoWin: “Users can continue to run the software, however. There is no “kill switch” to disable or cripple the software. However, Windows Vista SP1 will become extremely vulnerable to attack once Microsoft stops providing security updates.”
In April of 2012, all consumer versions of Vista will lose support. Business support will continue until 2017.