While Microsoft publishes security and stability updates on second Tuesday of every month, there are times when critical fixes, stability updates and Service Packs are released outside the schedule. That's why you should set your computer to look for available updates on daily basis.
In Windows Vista, 7, 8 and 8.1, Open Control Panel, click System and Security and then choose Windows Update, click the Change settings link on the left:
In the Choose how Windows can install updates window, make sure Install updates automatically (recommended) is selected.
Next, ensure that both Give