Visual Studio requires that minimum supported Windows Service Pack is installed on your computer before you install Visual Studio. You can download and install Windows service pack from http://windowsupdate.microsoft.com.. After you install the service pack, you are required to restart your computer. Visual Studio setup will not automatically restart. To restart Visual Studio setup, double-click setup.exe from the original installation media or click the appropriate link on the download Web site.
Note: It is highly recommended that you regularly check for and install updates for your operating system available at http://windowsupdate.microsoft.com/a>..
Service packs are the means by which product updates are distributed. Service packs can contain updates to improve system reliability, program compatibility, security, and more. For more information on Microsoft Service Packs, see http://support.microsoft.com/efault.aspx?scid=fh;EN-US;sp.