I have an acer aspire laptop, when i start it up its says configuring updates stage 3 of 3 0% complete then it will shut down come back on say the same again and shut down again. it will keep on doing this

Maybe you could try the last known good configuration. When the laptop is starting up, wait until the acer screen disappears and then tap F8 on the keyboard before the windows screen comes up. You should get a black screen with some options that say safe mode. The fourth or so option on the list will be "Last Known Good Configuration". The computer should try and load windows. Hopefully that will restore the machine before the update. 

If it works it would be a good idea to go to http://windowsupdate.microsoft.com/ and fully update your laptop. This will download the update manually instead of doing it with automatic updates.