Windows Update no Longer Works Since Installing SP1 Update

Yesterday I realised that Windows Update wasn't working on my Windows 7 (32-bit) laptop.

It sometimes found updates but then when I selected them and tried to download them it just hung on 0 kb and 0%.

I uninstalled SP1 and Windows Update worked fine. Then , when reinstalled SP1 Windows Update stopped working - it just hangs while it says its looking for updates.

I have used two tools to try to fix it - Windows Update Diagnostic and Microsoft FixIt 50202. Neither have worked...