Problem installing Service Pack 1

I am trying to help someone who has a laptop running Vista Home. The computer is a laptop given to her by her son so she could communicate with him by email. Different people have tried to help her and she even took the computer to Office Depot which did a lot of work on it. But the computer has had some additional history I know little or nothing about.

Her son set her up with a gmail account. I couldn't figure out how to use Windows Mail to access the gmail mail servers, so she has had to use gmail by going to gmail.com. Today, at my latest session with her, gmail siad it needed Internet exploer 9, but to install that I needed to install Service Pack 2, which required in turn Service Pack 1. I have been unable to install Service Pack 1. It turns out, that many attempts to install Service Pack 1 automatically in the past all failed. I've been trying to troubleshoot the problem, but so far with little success. I haven't even managed to get the Service Pack successfully downloaded.

I primarily work under LInux, so although I do have one computer running Vista, I am not a Windows guru. If anyone can give me any clues as to what might be wrong, and how to proceed, I would appreciate it. Is it possible the firewall is blocking the download or something like that?

Welcome
Seems to be a common problem, with a cornucopia of possible solutions
http://forums.cnet.com/7723-12546_102-297333.html
Problem: Cannot Install Windows Vista SP1
Link 1 the readiness tool is the place to start.

Let me add that no matter what I do, I keep getting error 80070002. I haven't tried every thing suggested, but I've tried quite a lot.

I don't think I can reinstall the OS because I doubt if the woman I am trying to help knows where the installation media are. In any case, I think I have devoted enough attention to this---I am an unpaid volunteer---if I can't fix the upgrade problem, I will suggest they try to find someone else to work on it.

I think her best option is a new laptop.

I finally managed to installl Vista Service Pack 1. Tod do this, I first installed the Update Readiness Tool, and then downloaded Service Pack 1 and installed it without using Windows Update. It is definitely installed as shown in Control Panel > System Maintenance > System, and running Windows Update no longer shows it as an avalable important update. But Update History doesn't show it as installed. Can anyone explain the discrepancy?