Microsoft has withdrawn an update to Windows 7 that caused some major issues for those who installed it. Update KB3004394 completely broke the mechanism which allows the installation of software with digital signatures – even Windows updates.
Essentially, those who installed this update ended up with a computer completely unable to install a great number of software applications. Ars Technica says that the update intended to change the way the OS updates its collection of root certificates, for which Windows uses to authenticate TLS and SSL connections. The update intended to increase the frequency in which the OS checks for those updates.
Well that didn’t go quite according to plan. A great number of users reported problems following the update, which led to Microsoft pulling it. The company has since issued a further update to solve the problems this one delivered.
Only those using Windows 7 Service Pack 1 and Windows Server 2008 R2 Service Pack 1 were affected and the update is still available for Windows 8, 8.1, Windows Server 2012, and 2012 R2 users who were unaffected.
Source: Ars Technica