I had several unsuccessful goes at updating Windows in April and eventually hit upon this method to solve it, but I wouldn’t blame you if you don’t try it because it’s not straightforward:-
1. Download updates from
http://www.microsoft.com/en-us/search/DownloadResults.aspx?q=KB2919355 – that was the search for the one I was after so search for those that you are trying to do. This will save having to download the updates several times (particularly useful if big ones are involved) - NOTE any prerequisites and order of installs, if given in the info
2. Using the run/command prompt from the menu available by right-clicking at the bottom left of the screen type [i]SFC /SCANNOW[i] and hit enter.
3. In Control panel go to Troubleshooting, then System And Security, then run Windows Update
4. REBOOT your machine
5. WHen it's back up and running again, go to the system services and turn off Windows Update
6. Delete all files in C:\Windows\SoftwareDistribution\DataStore and in C:\Windows\SoftwareDistribution\Download
7. Turn the Windows Update service back on
8. Try the updates again using those that you have downloaded in step 1.