This is an answer from a different forum which actually helped. Hope it does the same for you.
The error code 0x80070424 you described also means "ERROR_SERVICE_DOES_NOT_EXIST". Windows Update depends on these two following services:
1) Windows Update
2) Background Intelligent Transfer (BIT)
If it happens that these services are disable or missing, you will encounter this error code. Hence, you will need to ensure that the necessary services are available and running. Here's how:
1. Click Start, type
services.msc in the Start Search text area, and then click
services.msc in the programs list. If you are prompted for an administrator password or for a confirmation, type the password, or click
Continue.
2. Double-click Background Intelligent Transfer Service.
3. If the Startup status lists Stopped, click
Start and then click OK.
4. Double-click Windows Update.
5. If the Startup status lists Stopped, click
Start and then click OK.
6. Double-click Workstation.
7. If the Startup status lists
Stopped, click Start and then click OK.
8. Close the Services window and try to install updates again.
If the Background Intelligent Transfer Service does not appear in the list of Services, click the following link to view the KB article on the Microsoft web site and download the update:
http://support.microsoft.com/kb/939159/en-us.
Cheers,
