80070424 usually means that the BITS (Background Intelligent Transfer Service service (required by Windows Update) is not running.
Verify that BITS is correctly configured and started:
1. Click Start, click Run, type services.msc, and then click OK.
2. Double-click Background Intelligent Transfer Service.
3. In the Startup type box, click Manual, and then click Apply.
4. Click the Log On tab, and then verify that the service is enabled in every hardware profile that is listed. If the service is disabled in one or more hardware profiles, click the hardware profile, click Enable, and then click Apply.
5. Click the General tab, and then click Start.
If that's all okay, then you may need to re register the DLLs:-
1. Click Start.
2. Choose Run.
3. In the Run box, type (pressing okay after the command) :-
Regsvr32 QMGR.DLL
Regsvr32 wuaueng.dll
should work now