If you want to try the forthcoming Service Pack 1 for Vista you can download the release candidate from
http://www.microsoft.com/downloads/d.....Lang=en. You simply extract thefiles then run the cmd file to add some stuff to the registry. Now you do a Windows Update and it will install an update that makes updating smoother (according to them). After a reboot you do Windows Update again for another installer update. Then after this one you can install SP1. I warn you that it can take a while to download and install SP1 but I have it running fine here with no problems.