unable to connect

the update may have changed the device driver for the wireless adapter

whats the make and exact model of the PC
you could goto the manufacturers website and download the wireless driver and re-install
OR you could goto device manager and roll-back the driver - if it has been installed
to do that
goto device manager

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Device Manager
For Windows 8

If you happen to be using a keyboard with Windows 8, the quickest way to open Device Manager is via its shortcut on the Power User Menu, accessible by pressing the WINDOW key and the X key together.
If on a touch screen - have a read here http://pcsupport.about.com/od/window...-windows-8.htm

Once you are in device manager then navigate to:

network adaptors, click on the + > you should see a list of devices
one will have a name with "wireless" in
right click on that device
Properties>
Driver tab>
there will be an option to roll-back