How To Troubleshoot Windows Update Function?

My pc crashed from spyware/malware registery problems and when the pc finally
came back up the Windows function doesn't work. When I try and use Windows
Updates the page comes up but then just says "done" at the bottom and nothing
happens. How do I troubleshoot this to fix it? I realize there could be
lots of reasons it doesn't work but I don't know how it works to know what to
look at to fix.

I am running Windows XP, I.E.

I really appreciate your help.