I've tried several times to install Windows 7 Service Pack 1 via Windows update but it has failed every time. The download seems to complete ok but installation fails on restart & all changes are reversed before booting up. I've tried the recommended fix from microsoft but that does no good.
Any help would be most welcome.
I had to install KB2454826 first before SP1 would install:
Install Windows Update KB2454826 from Windows Update (http://www.update.microsoft.com/) if it is not already installed. If you install the service pack from the Microsoft Download Center and do not install Windows Update KB245862, you could encounter a Stop error in Windows in rare cases.
Windows Update KB2454826 will automatically be installed when you install the service pack by using Windows Update. However, Windows Update KB2454826 is not automatically installed when you install the service pack from the Microsoft Download Center.
To check whether Windows Update KB2454826 is installed, click Start, type View installed updates in the Search programs and files box, and then press Enter. Notice whether Update for Microsoft Windows (KB2454826) is listed. If the update is not listed, you will have to install it from Windows Update http://www.update.microsoft.com/