Welcome, option one should assist your for Vista update issues. Give this a read and see if it works for you .
Windows Update - Reset - Windows 7 Forums
It came from the seven forums but says it will work for vista. option one.

If you are sure that you have all the updates. Change the automatic upadter settings
You can just turn it off
Windows Update - Windows Automatic Updating
If it cant be reset.

I would check to be sure that all the updates were actually installed. I would, also check to make sure that you do in fact have all the current updates.

If you turn auto-updates off remember to manually check for more about every month to keep your system up to date.

And i found another guide that may be of assistance : Windows Update Troubleshooting
One or more of the above suggested tips on fixing your issue should work. Post back results so that all may learn.

Strangely enough the Windows Update - Windows Automatic Updating thing didn't work. I opened it and nothing happened when I typed what it said. o.o

And then when I tried your Windows Update Troubleshooting. I'm guessing I do everything...? I hope this works....

*Edit* I tried it! And to my dismay it still isn't working. However I can sense its starting to work. Before when I started to manually update it never stopped updating but hurray! Now it says theres a error. Error code is 80070002.

Hello again, try this please : Windows Update error 80070002