Had a laptop that stopped loading Windows Updates following a spyware infection and subsequent clean-up by MBAM. Internet access was ok.
Eventually tracked the fix down to a winsock reset ...
Look in Start > Accessories and find Command Prompt
Right-click and Run As Admin
Then type ...
netsh winsock reset
netsh int ipv4 reset
You should get a prompt to restart the computer. We didn't need to, restarting the Windows Update service was sufficient to get everything working again (Start > Control Panel > Admin Tools > Services)
[Just as an aside, we had already run the Microsoft Windows Update Fixit tool and renamed the SoftwareDistribution folder - just in case the above netsh commands don't work on their own]