A little white ago, Microsoft published an important security update ( KB983590 ) which solves a .NET Framework 3.5.1 and Microsoft Silverlight vulnerability of all Windows 7 and Windows Server 2008 R8 operating systems.
The vulnerability was pretty serious and according to Microsoft, a hacker might be able to take total control of the target computer.
The update which is recommended for all Windows 7 and Windows Server 2008 R2 is available in two versions. Download & Install or via Windows Update Center.
After you install the KB983590 update you will have to restart your computer.
Besides this update, Microsoft released other seven security updates for Windows 7 in the last 3 days.