After installing the updates, Windows 7 gives alert to have a restart to take the effect. You may want to disable this automatic restart after installing updates. Here is how you can prevent restarts and have them happen only when you want to restart rather than having to continually click “postpone“.
Click Start, type “regedit” in the search field (without the quotation marks) and hit Enter from keyboard:

Windows Registry editor will open. o to the key, create new key (s) of the same name if it or they do not exist :
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HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Windows\WindowsUpdate\AU
Create a new DWORD value called NoAutoRebootWithLoggedOnUsers by right click on the right sided pane, hover over New ; then click 32 bit DWORD Value :

Give the new DWORD the value 1 to prevent automatic reboots while users are logged in :

Save the change to registry and restart your Windows 7 PC. If you want to change to default again (i.e. you want that prompt to restart after installing updates), just delete the value and restart.

Just remember to restart the computer manually after completing your tasks so that the update can be applied. The reason for the restart is explained in this Microsoft Knowledge Base article: http://support.microsoft.com/kb/887012