After installing a new copy of Windows 7 SP1 the first Windows Update can take several hours “Checking for Updates…” and appears to be hung. However, don’t give up. It is processing over 200 updates! The time it takes to complete depends on the speed of your Internet connection and computer. Times can be up to 1 hr.
To avoid the frustration of waiting try to run this first update overnight. Ensure you have set Disk Sleep to “Never” within Control Panel | Power Options to avoid it sleeping mid-way through.
in the Windows notification area. This is to the right of the Taskbar at the bottom right of the screen. If not visible click on the arrow head to the left of the notification area to reveal hidden icons. Right-click on the Avast icon and select Open Avast UI.