You may want to check if the Windows Update service is running. Type services
into the start menu and click 'Component Services' then click 'Services' when it appears. Scroll down to Windows Update and either 'Start' or 'Restart' the service. Attachment 112410
I'd advise the 'Restart' then reboot your machine and see if that has helped.
Also, can you start task manager? (right-click taskbar then click 'Task Manager')