If Windows Update doesn't offer it, don't force it. The reasons are too many for me to list here but it's not offered when it might tank the machine.
ok i have been trying a few things to try to get the sp download for vista . i have vista home premium 64 bit , sheild deluxe 2008 anti virus . what i have done is close down all firewall all antivirus , everything i could think of , but with no luck . does any one ever have this problem or know how to fix it ? thank you all for the help